diff --git a/examples/example-exemplars-tail-sampling/example-greeting-service/pom.xml b/examples/example-exemplars-tail-sampling/example-greeting-service/pom.xml
index 530c74cea..fc329b061 100644
--- a/examples/example-exemplars-tail-sampling/example-greeting-service/pom.xml
+++ b/examples/example-exemplars-tail-sampling/example-greeting-service/pom.xml
@@ -41,6 +41,19 @@
     <build>
         <finalName>${project.artifactId}</finalName>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <release>17</release>
+                    <source>17</source>
+                    <target>17</target>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-Werror</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
diff --git a/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java b/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java
index af1652f76..45b2c8a79 100644
--- a/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java
+++ b/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java
@@ -13,6 +13,8 @@
 /** Hello World REST servlet, with an example counter and an example histogram. */
 public class GreetingServlet extends HttpServlet {
 
+  private static final long serialVersionUID = 0L;
+
   private final Random random = new Random(0);
 
   private final Histogram histogram;
diff --git a/examples/example-exemplars-tail-sampling/example-hello-world-app/pom.xml b/examples/example-exemplars-tail-sampling/example-hello-world-app/pom.xml
index 88ad9c667..e7ab8cbd6 100644
--- a/examples/example-exemplars-tail-sampling/example-hello-world-app/pom.xml
+++ b/examples/example-exemplars-tail-sampling/example-hello-world-app/pom.xml
@@ -41,6 +41,19 @@
     <build>
         <finalName>${project.artifactId}</finalName>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <release>17</release>
+                    <source>17</source>
+                    <target>17</target>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-Werror</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
diff --git a/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java b/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java
index fbe293d50..f5a90d977 100644
--- a/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java
+++ b/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java
@@ -20,6 +20,8 @@
 /** Hello World REST servlet, with an example counter and an example histogram. */
 public class HelloWorldServlet extends HttpServlet {
 
+  private static final long serialVersionUID = 0L;
+
   private final Random random = new Random(0);
 
   private final Histogram histogram;
diff --git a/examples/example-exporter-multi-target/src/main/java/io/prometheus/metrics/examples/multitarget/SampleMultiCollector.java b/examples/example-exporter-multi-target/src/main/java/io/prometheus/metrics/examples/multitarget/SampleMultiCollector.java
index 7a05f0a8b..f9cea3f87 100644
--- a/examples/example-exporter-multi-target/src/main/java/io/prometheus/metrics/examples/multitarget/SampleMultiCollector.java
+++ b/examples/example-exporter-multi-target/src/main/java/io/prometheus/metrics/examples/multitarget/SampleMultiCollector.java
@@ -71,11 +71,10 @@ protected MetricSnapshots collectMetricSnapshots(PrometheusScrapeRequest scrapeR
         gaugeBuilder.dataPoint(gaugeDataPointBuilder.build());
       }
     }
-    Collection<MetricSnapshot> snaps = new ArrayList<MetricSnapshot>();
+    Collection<MetricSnapshot<?>> snaps = new ArrayList<>();
     snaps.add(counterBuilder.build());
     snaps.add(gaugeBuilder.build());
-    MetricSnapshots msnaps = new MetricSnapshots(snaps);
-    return msnaps;
+    return new MetricSnapshots(snaps);
   }
 
   public List<String> getPrometheusNames() {
diff --git a/examples/example-exporter-servlet-tomcat/pom.xml b/examples/example-exporter-servlet-tomcat/pom.xml
index b253d7c50..357dd3118 100644
--- a/examples/example-exporter-servlet-tomcat/pom.xml
+++ b/examples/example-exporter-servlet-tomcat/pom.xml
@@ -41,6 +41,19 @@
     <build>
         <finalName>${project.artifactId}</finalName>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <release>17</release>
+                    <source>17</source>
+                    <target>17</target>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-Werror</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
diff --git a/examples/example-exporter-servlet-tomcat/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java b/examples/example-exporter-servlet-tomcat/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java
index eb2fa4f19..e2b654f34 100644
--- a/examples/example-exporter-servlet-tomcat/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java
+++ b/examples/example-exporter-servlet-tomcat/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java
@@ -14,6 +14,8 @@
 /** Hello World REST servlet, with an example counter and an example histogram. */
 public class HelloWorldServlet extends HttpServlet {
 
+  private static final long serialVersionUID = 0L;
+
   private final Random random = new Random(0);
 
   // Note: The requests_total counter is not a great example, because the
diff --git a/integration-tests/it-exporter/it-exporter-servlet-tomcat-sample/pom.xml b/integration-tests/it-exporter/it-exporter-servlet-tomcat-sample/pom.xml
index 606be4c2a..e9ebcb583 100644
--- a/integration-tests/it-exporter/it-exporter-servlet-tomcat-sample/pom.xml
+++ b/integration-tests/it-exporter/it-exporter-servlet-tomcat-sample/pom.xml
@@ -36,6 +36,19 @@
     <build>
         <finalName>exporter-servlet-tomcat-sample</finalName>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <release>17</release>
+                    <source>17</source>
+                    <target>17</target>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-Werror</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
diff --git a/pom.xml b/pom.xml
index 3e8a2809a..6ae53a26b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -125,7 +125,7 @@
                 </plugin>
                 <plugin>
                     <artifactId>maven-compiler-plugin</artifactId>
-                    <version>3.1</version>
+                    <version>3.13.0</version>
                 </plugin>
                 <plugin>
                     <artifactId>maven-surefire-plugin</artifactId>
@@ -270,8 +270,14 @@
             <plugin>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
+                    <release>8</release>
+                    <source>8</source>
+                    <target>8</target>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-Werror</arg>
+                    </compilerArgs>
                 </configuration>
             </plugin>
             <plugin>
diff --git a/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesException.java b/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesException.java
index 5024cc45a..bdb024514 100644
--- a/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesException.java
+++ b/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesException.java
@@ -2,6 +2,8 @@
 
 public class PrometheusPropertiesException extends RuntimeException {
 
+  private static final long serialVersionUID = 0L;
+
   public PrometheusPropertiesException(String msg) {
     super(msg);
   }
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/datapoints/TimerApi.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/datapoints/TimerApi.java
index d4266c04c..8267f7f78 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/datapoints/TimerApi.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/datapoints/TimerApi.java
@@ -57,22 +57,25 @@ public interface TimerApi {
    * must use base units (e.g. seconds, bytes) and leave converting them to something more readable
    * to graphing tools".</i>
    */
+  @SuppressWarnings("try")
   default void time(Runnable func) {
-    try (Timer timer = startTimer()) {
+    try (Timer ignored = startTimer()) {
       func.run();
     }
   }
 
   /** Like {@link #time(Runnable)}, but returns the return value of {@code func}. */
+  @SuppressWarnings("try")
   default <T> T time(Supplier<T> func) {
-    try (Timer timer = startTimer()) {
+    try (Timer ignored = startTimer()) {
       return func.get();
     }
   }
 
   /** Like {@link #time(Supplier)}, but {@code func} may throw a checked {@code Exception}. */
+  @SuppressWarnings("try")
   default <T> T timeChecked(Callable<T> func) throws Exception {
-    try (Timer timer = startTimer()) {
+    try (Timer ignored = startTimer()) {
       return func.call();
     }
   }
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Metric.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Metric.java
index d3c00eca0..4821e93cd 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Metric.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Metric.java
@@ -19,7 +19,7 @@ protected Metric(Builder<?, ?> builder) {
   }
 
   @Override
-  public abstract MetricSnapshot collect();
+  public abstract MetricSnapshot<?> collect();
 
   protected abstract static class Builder<B extends Builder<B, M>, M extends Metric> {
 
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/SlidingWindow.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/SlidingWindow.java
index 93fa20d0e..c9586e179 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/SlidingWindow.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/SlidingWindow.java
@@ -39,6 +39,7 @@ public class SlidingWindow<T> {
    * @param maxAgeSeconds after this amount of time an instance of T gets evicted.
    * @param ageBuckets number of age buckets.
    */
+  @SuppressWarnings("unchecked")
   public SlidingWindow(
       Class<T> clazz,
       Supplier<T> constructor,
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java
index dc61b943d..1d2bfe02e 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java
@@ -45,9 +45,9 @@ protected StatefulMetric(Builder<?, ?> builder) {
   /**
    * labels and metricData have the same size. labels.get(i) are the labels for metricData.get(i).
    */
-  protected abstract MetricSnapshot collect(List<Labels> labels, List<T> metricData);
+  protected abstract MetricSnapshot<?> collect(List<Labels> labels, List<T> metricData);
 
-  public MetricSnapshot collect() {
+  public MetricSnapshot<?> collect() {
     if (labelNames.length == 0 && data.isEmpty()) {
       // This is a metric without labels that has not been used yet. Initialize the data on the fly.
       labelValues();
@@ -129,6 +129,7 @@ public void clear() {
 
   protected abstract T newDataPoint();
 
+  @SuppressWarnings("unchecked")
   protected T getNoLabels() {
     if (noLabels == null) {
       // Note that this will throw an IllegalArgumentException if labelNames is not empty.
diff --git a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/GaugeTest.java b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/GaugeTest.java
index 1e48d63c0..9aa0b04b3 100644
--- a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/GaugeTest.java
+++ b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/GaugeTest.java
@@ -80,8 +80,9 @@ public void testSet() {
   }
 
   @Test
+  @SuppressWarnings("try")
   public void testTimer() throws InterruptedException {
-    try (Timer timer = noLabels.startTimer()) {
+    try (Timer ignored = noLabels.startTimer()) {
       Thread.sleep(12);
     }
     assertThat(getValue(noLabels))
diff --git a/prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PrometheusMetricProducer.java b/prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PrometheusMetricProducer.java
index 4b8b5591f..a3022289a 100644
--- a/prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PrometheusMetricProducer.java
+++ b/prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PrometheusMetricProducer.java
@@ -51,7 +51,7 @@ public Collection<MetricData> collectAllMetrics() {
             resourceWithTargetInfo,
             scopeFromInfo != null ? scopeFromInfo : instrumentationScopeInfo,
             System.currentTimeMillis());
-    for (MetricSnapshot snapshot : snapshots) {
+    for (MetricSnapshot<?> snapshot : snapshots) {
       if (snapshot instanceof CounterSnapshot) {
         addUnlessNull(result, factory.create((CounterSnapshot) snapshot));
       } else if (snapshot instanceof GaugeSnapshot) {
@@ -78,10 +78,10 @@ public Collection<MetricData> collectAllMetrics() {
 
   private Resource resourceFromTargetInfo(MetricSnapshots snapshots) {
     ResourceBuilder result = Resource.builder();
-    for (MetricSnapshot snapshot : snapshots) {
+    for (MetricSnapshot<?> snapshot : snapshots) {
       if (snapshot.getMetadata().getName().equals("target") && snapshot instanceof InfoSnapshot) {
         InfoSnapshot targetInfo = (InfoSnapshot) snapshot;
-        if (targetInfo.getDataPoints().size() > 0) {
+        if (!targetInfo.getDataPoints().isEmpty()) {
           InfoSnapshot.InfoDataPointSnapshot data = targetInfo.getDataPoints().get(0);
           Labels labels = data.getLabels();
           for (int i = 0; i < labels.size(); i++) {
@@ -95,11 +95,11 @@ private Resource resourceFromTargetInfo(MetricSnapshots snapshots) {
 
   private InstrumentationScopeInfo instrumentationScopeFromOTelScopeInfo(
       MetricSnapshots snapshots) {
-    for (MetricSnapshot snapshot : snapshots) {
+    for (MetricSnapshot<?> snapshot : snapshots) {
       if (snapshot.getMetadata().getPrometheusName().equals("otel_scope")
           && snapshot instanceof InfoSnapshot) {
         InfoSnapshot scopeInfo = (InfoSnapshot) snapshot;
-        if (scopeInfo.getDataPoints().size() > 0) {
+        if (!scopeInfo.getDataPoints().isEmpty()) {
           Labels labels = scopeInfo.getDataPoints().get(0).getLabels();
           String name = null;
           String version = null;
diff --git a/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/ExemplarTest.java b/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/ExemplarTest.java
index def62834f..48054b192 100644
--- a/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/ExemplarTest.java
+++ b/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/ExemplarTest.java
@@ -70,13 +70,14 @@ public void tearDown() {
   }
 
   @Test
+  @SuppressWarnings("try")
   public void sampledExemplarIsForwarded() {
     try (SdkTracerProvider sdkTracerProvider =
         SdkTracerProvider.builder().setSampler(Sampler.alwaysOn()).build()) {
 
       Tracer test = sdkTracerProvider.get(INSTRUMENTATION_SCOPE_NAME);
       Span span = test.spanBuilder(SPAN_NAME).startSpan();
-      try (Scope scope = span.makeCurrent()) {
+      try (Scope ignored = span.makeCurrent()) {
         testCounter.inc(2);
       }
     }
@@ -95,13 +96,14 @@ public void sampledExemplarIsForwarded() {
   }
 
   @Test
+  @SuppressWarnings("try")
   public void notSampledExemplarIsNotForwarded() {
     try (SdkTracerProvider sdkTracerProvider =
         SdkTracerProvider.builder().setSampler(Sampler.alwaysOff()).build()) {
 
       Tracer test = sdkTracerProvider.get(INSTRUMENTATION_SCOPE_NAME);
       Span span = test.spanBuilder(SPAN_NAME).startSpan();
-      try (Scope scope = span.makeCurrent()) {
+      try (Scope ignored = span.makeCurrent()) {
         testCounter.inc(2);
       }
     }
diff --git a/prometheus-metrics-exporter-servlet-jakarta/pom.xml b/prometheus-metrics-exporter-servlet-jakarta/pom.xml
index 02e225888..d135fb36d 100644
--- a/prometheus-metrics-exporter-servlet-jakarta/pom.xml
+++ b/prometheus-metrics-exporter-servlet-jakarta/pom.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
     <parent>
@@ -34,4 +35,22 @@
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <release>17</release>
+                    <source>17</source>
+                    <target>17</target>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-Werror</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
 </project>
diff --git a/prometheus-metrics-exporter-servlet-jakarta/src/main/java/io/prometheus/metrics/exporter/servlet/jakarta/PrometheusMetricsServlet.java b/prometheus-metrics-exporter-servlet-jakarta/src/main/java/io/prometheus/metrics/exporter/servlet/jakarta/PrometheusMetricsServlet.java
index 28728dc94..5e22fc3fd 100644
--- a/prometheus-metrics-exporter-servlet-jakarta/src/main/java/io/prometheus/metrics/exporter/servlet/jakarta/PrometheusMetricsServlet.java
+++ b/prometheus-metrics-exporter-servlet-jakarta/src/main/java/io/prometheus/metrics/exporter/servlet/jakarta/PrometheusMetricsServlet.java
@@ -16,6 +16,8 @@
  */
 public class PrometheusMetricsServlet extends HttpServlet {
 
+  private static final long serialVersionUID = 0L;
+
   private final PrometheusScrapeHandler handler;
 
   public PrometheusMetricsServlet() {
diff --git a/prometheus-metrics-exporter-servlet-javax/src/main/java/io/prometheus/metrics/exporter/servlet/javax/PrometheusMetricsServlet.java b/prometheus-metrics-exporter-servlet-javax/src/main/java/io/prometheus/metrics/exporter/servlet/javax/PrometheusMetricsServlet.java
index fe81fe96b..a486aec93 100644
--- a/prometheus-metrics-exporter-servlet-javax/src/main/java/io/prometheus/metrics/exporter/servlet/javax/PrometheusMetricsServlet.java
+++ b/prometheus-metrics-exporter-servlet-javax/src/main/java/io/prometheus/metrics/exporter/servlet/javax/PrometheusMetricsServlet.java
@@ -15,6 +15,8 @@
  */
 public class PrometheusMetricsServlet extends HttpServlet {
 
+  private static final long serialVersionUID = 0L;
+
   private final PrometheusScrapeHandler handler;
 
   /** Default constructor. Uses the default PrometheusProperties and PrometheusRegistry. */
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java
index 00ac6b9fc..10f54848b 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java
@@ -65,7 +65,7 @@ public String getContentType() {
 
   public void write(OutputStream out, MetricSnapshots metricSnapshots) throws IOException {
     OutputStreamWriter writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
-    for (MetricSnapshot snapshot : metricSnapshots) {
+    for (MetricSnapshot<?> snapshot : metricSnapshots) {
       if (snapshot.getDataPoints().size() > 0) {
         if (snapshot instanceof CounterSnapshot) {
           writeCounter(writer, (CounterSnapshot) snapshot);
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java
index 7e722b056..87e50ed8b 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java
@@ -52,7 +52,7 @@ public String getContentType() {
 
   public String toDebugString(MetricSnapshots metricSnapshots) {
     StringBuilder stringBuilder = new StringBuilder();
-    for (MetricSnapshot snapshot : metricSnapshots) {
+    for (MetricSnapshot<?> snapshot : metricSnapshots) {
       if (snapshot.getDataPoints().size() > 0) {
         stringBuilder.append(TextFormat.printer().printToString(convert(snapshot)));
       }
@@ -62,14 +62,14 @@ public String toDebugString(MetricSnapshots metricSnapshots) {
 
   @Override
   public void write(OutputStream out, MetricSnapshots metricSnapshots) throws IOException {
-    for (MetricSnapshot snapshot : metricSnapshots) {
+    for (MetricSnapshot<?> snapshot : metricSnapshots) {
       if (snapshot.getDataPoints().size() > 0) {
         convert(snapshot).writeDelimitedTo(out);
       }
     }
   }
 
-  public Metrics.MetricFamily convert(MetricSnapshot snapshot) {
+  public Metrics.MetricFamily convert(MetricSnapshot<?> snapshot) {
     Metrics.MetricFamily.Builder builder = Metrics.MetricFamily.newBuilder();
     if (snapshot instanceof CounterSnapshot) {
       for (CounterDataPointSnapshot data : ((CounterSnapshot) snapshot).getDataPoints()) {
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java
index 28d049f25..786e1d9bd 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java
@@ -59,7 +59,7 @@ public void write(OutputStream out, MetricSnapshots metricSnapshots) throws IOEx
     // "unknown", "gauge", "counter", "stateset", "info", "histogram", "gaugehistogram", and
     // "summary".
     OutputStreamWriter writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
-    for (MetricSnapshot snapshot : metricSnapshots) {
+    for (MetricSnapshot<?> snapshot : metricSnapshots) {
       if (snapshot.getDataPoints().size() > 0) {
         if (snapshot instanceof CounterSnapshot) {
           writeCounter(writer, (CounterSnapshot) snapshot);
@@ -79,7 +79,7 @@ public void write(OutputStream out, MetricSnapshots metricSnapshots) throws IOEx
       }
     }
     if (writeCreatedTimestamps) {
-      for (MetricSnapshot snapshot : metricSnapshots) {
+      for (MetricSnapshot<?> snapshot : metricSnapshots) {
         if (snapshot.getDataPoints().size() > 0) {
           if (snapshot instanceof CounterSnapshot) {
             writeCreated(writer, snapshot);
@@ -94,7 +94,8 @@ public void write(OutputStream out, MetricSnapshots metricSnapshots) throws IOEx
     writer.flush();
   }
 
-  public void writeCreated(OutputStreamWriter writer, MetricSnapshot snapshot) throws IOException {
+  public void writeCreated(OutputStreamWriter writer, MetricSnapshot<?> snapshot)
+      throws IOException {
     boolean metadataWritten = false;
     MetricMetadata metadata = snapshot.getMetadata();
     for (DataPointSnapshot data : snapshot.getDataPoints()) {
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java
index da64f30bb..c61a8f1b6 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java
@@ -85,6 +85,6 @@ static void writeLabels(
   }
 
   public static String shortDebugString(MessageOrBuilder protobufData) {
-    return TextFormat.printer().shortDebugString(protobufData);
+    return TextFormat.printer().emittingSingleLine(true).printToString(protobufData);
   }
 }
diff --git a/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java b/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java
index 7a7a0ea7e..a5e427a89 100644
--- a/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java
+++ b/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java
@@ -2592,7 +2592,8 @@ public void testLabelValueEscape() throws IOException {
     assertPrometheusText(prometheus, counter);
   }
 
-  private void assertOpenMetricsText(String expected, MetricSnapshot snapshot) throws IOException {
+  private void assertOpenMetricsText(String expected, MetricSnapshot<?> snapshot)
+      throws IOException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     OpenMetricsTextFormatWriter writer = new OpenMetricsTextFormatWriter(true, false);
     writer.write(out, MetricSnapshots.of(snapshot));
@@ -2600,14 +2601,14 @@ private void assertOpenMetricsText(String expected, MetricSnapshot snapshot) thr
   }
 
   private void assertOpenMetricsTextWithExemplarsOnAllTimeSeries(
-      String expected, MetricSnapshot snapshot) throws IOException {
+      String expected, MetricSnapshot<?> snapshot) throws IOException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     OpenMetricsTextFormatWriter writer = new OpenMetricsTextFormatWriter(true, true);
     writer.write(out, MetricSnapshots.of(snapshot));
     assertThat(out).hasToString(expected);
   }
 
-  private void assertOpenMetricsTextWithoutCreated(String expected, MetricSnapshot snapshot)
+  private void assertOpenMetricsTextWithoutCreated(String expected, MetricSnapshot<?> snapshot)
       throws IOException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     OpenMetricsTextFormatWriter writer = new OpenMetricsTextFormatWriter(false, false);
@@ -2615,14 +2616,15 @@ private void assertOpenMetricsTextWithoutCreated(String expected, MetricSnapshot
     assertThat(out).hasToString(expected);
   }
 
-  private void assertPrometheusText(String expected, MetricSnapshot snapshot) throws IOException {
+  private void assertPrometheusText(String expected, MetricSnapshot<?> snapshot)
+      throws IOException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     PrometheusTextFormatWriter writer = new PrometheusTextFormatWriter(true);
     writer.write(out, MetricSnapshots.of(snapshot));
     assertThat(out).hasToString(expected);
   }
 
-  private void assertPrometheusTextWithoutCreated(String expected, MetricSnapshot snapshot)
+  private void assertPrometheusTextWithoutCreated(String expected, MetricSnapshot<?> snapshot)
       throws IOException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     PrometheusTextFormatWriter writer = new PrometheusTextFormatWriter(false);
@@ -2630,7 +2632,7 @@ private void assertPrometheusTextWithoutCreated(String expected, MetricSnapshot
     assertThat(out).hasToString(expected);
   }
 
-  private void assertPrometheusProtobuf(String expected, MetricSnapshot snapshot) {
+  private void assertPrometheusProtobuf(String expected, MetricSnapshot<?> snapshot) {
     PrometheusProtobufWriter writer = new PrometheusProtobufWriter();
     Metrics.MetricFamily protobufData = writer.convert(snapshot);
     String actual = TextFormatUtil.shortDebugString(protobufData);
diff --git a/prometheus-metrics-instrumentation-caffeine/src/main/java/io/prometheus/metrics/instrumentation/caffeine/CacheMetricsCollector.java b/prometheus-metrics-instrumentation-caffeine/src/main/java/io/prometheus/metrics/instrumentation/caffeine/CacheMetricsCollector.java
index 69b852a41..c195ae77c 100644
--- a/prometheus-metrics-instrumentation-caffeine/src/main/java/io/prometheus/metrics/instrumentation/caffeine/CacheMetricsCollector.java
+++ b/prometheus-metrics-instrumentation-caffeine/src/main/java/io/prometheus/metrics/instrumentation/caffeine/CacheMetricsCollector.java
@@ -11,6 +11,7 @@
 import io.prometheus.metrics.model.snapshots.MetricSnapshots;
 import io.prometheus.metrics.model.snapshots.SummarySnapshot;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -53,7 +54,7 @@
 public class CacheMetricsCollector implements MultiCollector {
   private static final double NANOSECONDS_PER_SECOND = 1_000_000_000.0;
 
-  protected final ConcurrentMap<String, Cache> children = new ConcurrentHashMap<String, Cache>();
+  protected final ConcurrentMap<String, Cache<?, ?>> children = new ConcurrentHashMap<>();
 
   /**
    * Add or replace the cache with the given name.
@@ -63,7 +64,7 @@ public class CacheMetricsCollector implements MultiCollector {
    * @param cacheName The name of the cache, will be the metrics label value
    * @param cache The cache being monitored
    */
-  public void addCache(String cacheName, Cache cache) {
+  public void addCache(String cacheName, Cache<?, ?> cache) {
     children.put(cacheName, cache);
   }
 
@@ -75,7 +76,7 @@ public void addCache(String cacheName, Cache cache) {
    * @param cacheName The name of the cache, will be the metrics label value
    * @param cache The cache being monitored
    */
-  public void addCache(String cacheName, AsyncCache cache) {
+  public void addCache(String cacheName, AsyncCache<?, ?> cache) {
     children.put(cacheName, cache.synchronous());
   }
 
@@ -86,7 +87,7 @@ public void addCache(String cacheName, AsyncCache cache) {
    *
    * @param cacheName cache to be removed
    */
-  public Cache removeCache(String cacheName) {
+  public Cache<?, ?> nremoveCache(String cacheName) {
     return children.remove(cacheName);
   }
 
@@ -141,8 +142,8 @@ public MetricSnapshots collect() {
             .name("caffeine_cache_load_duration_seconds")
             .help("Cache load duration: both success and failures");
 
-    for (final Map.Entry<String, Cache> c : children.entrySet()) {
-      final List<String> cacheName = Arrays.asList(c.getKey());
+    for (final Map.Entry<String, Cache<?, ?>> c : children.entrySet()) {
+      final List<String> cacheName = Collections.singletonList(c.getKey());
       final Labels labels = Labels.of(labelNames, cacheName);
 
       final CacheStats stats = c.getValue().stats();
diff --git a/prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java b/prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java
index c87f4aa90..6d99c176d 100644
--- a/prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java
+++ b/prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java
@@ -70,7 +70,7 @@ private MetricMetadata getMetricMetaData(String metricName, Metric metric) {
    * Export counter as Prometheus <a
    * href="https://prometheus.io/docs/concepts/metric_types/#gauge">Gauge</a>.
    */
-  MetricSnapshot fromCounter(String dropwizardName, Counter counter) {
+  MetricSnapshot<?> fromCounter(String dropwizardName, Counter counter) {
     MetricMetadata metadata = getMetricMetaData(dropwizardName, counter);
     CounterSnapshot.CounterDataPointSnapshot.Builder dataPointBuilder =
         CounterSnapshot.CounterDataPointSnapshot.builder()
@@ -84,7 +84,7 @@ MetricSnapshot fromCounter(String dropwizardName, Counter counter) {
   }
 
   /** Export gauge as a prometheus gauge. */
-  MetricSnapshot fromGauge(String dropwizardName, Gauge gauge) {
+  MetricSnapshot<?> fromGauge(String dropwizardName, Gauge<?> gauge) {
     Object obj = gauge.getValue();
     double value;
     if (obj instanceof Number) {
@@ -119,7 +119,7 @@ MetricSnapshot fromGauge(String dropwizardName, Gauge gauge) {
    * @param count the total sample count for this snapshot.
    * @param factor a factor to apply to histogram values.
    */
-  MetricSnapshot fromSnapshotAndCount(
+  MetricSnapshot<?> fromSnapshotAndCount(
       String dropwizardName, Snapshot snapshot, long count, double factor, String helpMessage) {
     Quantiles quantiles =
         Quantiles.builder()
@@ -144,7 +144,7 @@ MetricSnapshot fromSnapshotAndCount(
   }
 
   /** Convert histogram snapshot. */
-  MetricSnapshot fromHistogram(String dropwizardName, Histogram histogram) {
+  MetricSnapshot<?> fromHistogram(String dropwizardName, Histogram histogram) {
     return fromSnapshotAndCount(
         dropwizardName,
         histogram.getSnapshot(),
@@ -154,7 +154,7 @@ MetricSnapshot fromHistogram(String dropwizardName, Histogram histogram) {
   }
 
   /** Export Dropwizard Timer as a histogram. Use TIME_UNIT as time unit. */
-  MetricSnapshot fromTimer(String dropwizardName, Timer timer) {
+  MetricSnapshot<?> fromTimer(String dropwizardName, Timer timer) {
     return fromSnapshotAndCount(
         dropwizardName,
         timer.getSnapshot(),
@@ -164,7 +164,7 @@ MetricSnapshot fromTimer(String dropwizardName, Timer timer) {
   }
 
   /** Export a Meter as a prometheus COUNTER. */
-  MetricSnapshot fromMeter(String dropwizardName, Meter meter) {
+  MetricSnapshot<?> fromMeter(String dropwizardName, Meter meter) {
     MetricMetadata metadata = getMetricMetaData(dropwizardName + "_total", meter);
     CounterSnapshot.CounterDataPointSnapshot.Builder dataPointBuilder =
         CounterSnapshot.CounterDataPointSnapshot.builder().value(meter.getCount());
@@ -179,7 +179,8 @@ MetricSnapshot fromMeter(String dropwizardName, Meter meter) {
   @Override
   public MetricSnapshots collect() {
     MetricSnapshots.Builder metricSnapshots = MetricSnapshots.builder();
-    for (SortedMap.Entry<MetricName, Gauge> entry : registry.getGauges(metricFilter).entrySet()) {
+    for (@SuppressWarnings("rawtypes")
+    SortedMap.Entry<MetricName, Gauge> entry : registry.getGauges(metricFilter).entrySet()) {
       Optional.ofNullable(fromGauge(entry.getKey().getKey(), entry.getValue()))
           .map(metricSnapshots::metricSnapshot);
     }
diff --git a/prometheus-metrics-instrumentation-guava/src/main/java/io/prometheus/metrics/instrumentation/guava/CacheMetricsCollector.java b/prometheus-metrics-instrumentation-guava/src/main/java/io/prometheus/metrics/instrumentation/guava/CacheMetricsCollector.java
index 5e17338b7..e1da20071 100644
--- a/prometheus-metrics-instrumentation-guava/src/main/java/io/prometheus/metrics/instrumentation/guava/CacheMetricsCollector.java
+++ b/prometheus-metrics-instrumentation-guava/src/main/java/io/prometheus/metrics/instrumentation/guava/CacheMetricsCollector.java
@@ -9,7 +9,7 @@
 import io.prometheus.metrics.model.snapshots.Labels;
 import io.prometheus.metrics.model.snapshots.MetricSnapshots;
 import io.prometheus.metrics.model.snapshots.SummarySnapshot;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -53,7 +53,7 @@ public class CacheMetricsCollector implements MultiCollector {
 
   private static final double NANOSECONDS_PER_SECOND = 1_000_000_000.0;
 
-  protected final ConcurrentMap<String, Cache> children = new ConcurrentHashMap<>();
+  protected final ConcurrentMap<String, Cache<?, ?>> children = new ConcurrentHashMap<>();
 
   /**
    * Add or replace the cache with the given name.
@@ -63,7 +63,7 @@ public class CacheMetricsCollector implements MultiCollector {
    * @param cacheName The name of the cache, will be the metrics label value
    * @param cache The cache being monitored
    */
-  public void addCache(String cacheName, Cache cache) {
+  public void addCache(String cacheName, Cache<?, ?> cache) {
     children.put(cacheName, cache);
   }
 
@@ -74,7 +74,7 @@ public void addCache(String cacheName, Cache cache) {
    *
    * @param cacheName cache to be removed
    */
-  public Cache removeCache(String cacheName) {
+  public Cache<?, ?> removeCache(String cacheName) {
     return children.remove(cacheName);
   }
 
@@ -90,7 +90,7 @@ public void clear() {
   @Override
   public MetricSnapshots collect() {
     final MetricSnapshots.Builder metricSnapshotsBuilder = MetricSnapshots.builder();
-    final List<String> labelNames = Arrays.asList("cache");
+    final List<String> labelNames = Collections.singletonList("cache");
 
     final CounterSnapshot.Builder cacheHitTotal =
         CounterSnapshot.builder().name("guava_cache_hit").help("Cache hit totals");
@@ -122,8 +122,8 @@ public MetricSnapshots collect() {
             .name("guava_cache_load_duration_seconds")
             .help("Cache load duration: both success and failures");
 
-    for (final Map.Entry<String, Cache> c : children.entrySet()) {
-      final List<String> cacheName = Arrays.asList(c.getKey());
+    for (final Map.Entry<String, Cache<?, ?>> c : children.entrySet()) {
+      final List<String> cacheName = Collections.singletonList(c.getKey());
       final Labels labels = Labels.of(labelNames, cacheName);
 
       final CacheStats stats = c.getValue().stats();
diff --git a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java
index 67dd6f2e6..6aeacb13f 100644
--- a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java
+++ b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java
@@ -50,7 +50,7 @@ public void testListenerLogic() {
   }
 
   private double getCountByPool(String metricName, String poolName, MetricSnapshots snapshots) {
-    for (MetricSnapshot snapshot : snapshots) {
+    for (MetricSnapshot<?> snapshot : snapshots) {
       if (snapshot.getMetadata().getPrometheusName().equals(metricName)) {
         for (CounterSnapshot.CounterDataPointSnapshot data :
             ((CounterSnapshot) snapshot).getDataPoints()) {
diff --git a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java
index 16e04b76c..fe97561aa 100644
--- a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java
+++ b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java
@@ -145,7 +145,7 @@ public void testInvalidThreadIds() {
 
   private Map<String, Double> getCountByState(MetricSnapshots snapshots) {
     Map<String, Double> result = new HashMap<>();
-    for (MetricSnapshot snapshot : snapshots) {
+    for (MetricSnapshot<?> snapshot : snapshots) {
       if (snapshot.getMetadata().getName().equals("jvm_threads_state")) {
         for (GaugeSnapshot.GaugeDataPointSnapshot data :
             ((GaugeSnapshot) snapshot).getDataPoints()) {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
index 57b2b640f..fad461548 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
@@ -11,13 +11,13 @@
 public interface Collector {
 
   /** Called when the Prometheus server scrapes metrics. */
-  MetricSnapshot collect();
+  MetricSnapshot<?> collect();
 
   /**
    * Provides Collector with the details of the request issued by Prometheus to allow multi-target
    * pattern implementation Override to implement request dependent logic to provide MetricSnapshot
    */
-  default MetricSnapshot collect(PrometheusScrapeRequest scrapeRequest) {
+  default MetricSnapshot<?> collect(PrometheusScrapeRequest scrapeRequest) {
     return collect();
   }
 
@@ -28,8 +28,8 @@ default MetricSnapshot collect(PrometheusScrapeRequest scrapeRequest) {
    * <p>Override this if there is a more efficient way than first collecting the snapshot and then
    * discarding it.
    */
-  default MetricSnapshot collect(Predicate<String> includedNames) {
-    MetricSnapshot result = collect();
+  default MetricSnapshot<?> collect(Predicate<String> includedNames) {
+    MetricSnapshot<?> result = collect();
     if (includedNames.test(result.getMetadata().getPrometheusName())) {
       return result;
     } else {
@@ -43,9 +43,9 @@ default MetricSnapshot collect(Predicate<String> includedNames) {
    * <p>Override this if there is a more efficient way than first collecting the snapshot and then
    * discarding it.
    */
-  default MetricSnapshot collect(
+  default MetricSnapshot<?> collect(
       Predicate<String> includedNames, PrometheusScrapeRequest scrapeRequest) {
-    MetricSnapshot result = collect(scrapeRequest);
+    MetricSnapshot<?> result = collect(scrapeRequest);
     if (includedNames.test(result.getMetadata().getPrometheusName())) {
       return result;
     } else {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
index a4f52746e..8f44239fb 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
@@ -42,7 +42,7 @@ default MetricSnapshots collect(
       Predicate<String> includedNames, PrometheusScrapeRequest scrapeRequest) {
     MetricSnapshots allSnapshots = scrapeRequest == null ? collect() : collect(scrapeRequest);
     MetricSnapshots.Builder result = MetricSnapshots.builder();
-    for (MetricSnapshot snapshot : allSnapshots) {
+    for (MetricSnapshot<?> snapshot : allSnapshots) {
       if (includedNames.test(snapshot.getMetadata().getPrometheusName())) {
         result.metricSnapshot(snapshot);
       }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java
index 00a19d9f6..026560bb9 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java
@@ -63,7 +63,7 @@ public MetricSnapshots scrape() {
   public MetricSnapshots scrape(PrometheusScrapeRequest scrapeRequest) {
     MetricSnapshots.Builder result = MetricSnapshots.builder();
     for (Collector collector : collectors) {
-      MetricSnapshot snapshot =
+      MetricSnapshot<?> snapshot =
           scrapeRequest == null ? collector.collect() : collector.collect(scrapeRequest);
       if (snapshot != null) {
         if (result.containsMetricName(snapshot.getMetadata().getName())) {
@@ -76,7 +76,7 @@ public MetricSnapshots scrape(PrometheusScrapeRequest scrapeRequest) {
     for (MultiCollector collector : multiCollectors) {
       MetricSnapshots snapshots =
           scrapeRequest == null ? collector.collect() : collector.collect(scrapeRequest);
-      for (MetricSnapshot snapshot : snapshots) {
+      for (MetricSnapshot<?> snapshot : snapshots) {
         if (result.containsMetricName(snapshot.getMetadata().getName())) {
           throw new IllegalStateException(
               snapshot.getMetadata().getPrometheusName() + ": duplicate metric name.");
@@ -105,7 +105,7 @@ public MetricSnapshots scrape(
       // prometheusName == null means the name is unknown, and we have to scrape to learn the name.
       // prometheusName != null means we can skip the scrape if the name is excluded.
       if (prometheusName == null || includedNames.test(prometheusName)) {
-        MetricSnapshot snapshot =
+        MetricSnapshot<?> snapshot =
             scrapeRequest == null
                 ? collector.collect(includedNames)
                 : collector.collect(includedNames, scrapeRequest);
@@ -132,7 +132,7 @@ public MetricSnapshots scrape(
             scrapeRequest == null
                 ? collector.collect(includedNames)
                 : collector.collect(includedNames, scrapeRequest);
-        for (MetricSnapshot snapshot : snapshots) {
+        for (MetricSnapshot<?> snapshot : snapshots) {
           if (snapshot != null) {
             result.metricSnapshot(snapshot);
           }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/CounterSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/CounterSnapshot.java
index fa807af19..45be6f0f1 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/CounterSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/CounterSnapshot.java
@@ -5,7 +5,7 @@
 import java.util.List;
 
 /** Immutable snapshot of a Counter. */
-public class CounterSnapshot extends MetricSnapshot {
+public class CounterSnapshot extends MetricSnapshot<CounterSnapshot.CounterDataPointSnapshot> {
 
   /**
    * To create a new {@link CounterSnapshot}, you can either call the constructor directly or use
@@ -21,7 +21,7 @@ public CounterSnapshot(MetricMetadata metadata, Collection<CounterDataPointSnaps
 
   @Override
   public List<CounterDataPointSnapshot> getDataPoints() {
-    return (List<CounterDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static class CounterDataPointSnapshot extends DataPointSnapshot {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/DuplicateLabelsException.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/DuplicateLabelsException.java
index d1f3f3414..721655105 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/DuplicateLabelsException.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/DuplicateLabelsException.java
@@ -6,6 +6,8 @@
  */
 public class DuplicateLabelsException extends IllegalArgumentException {
 
+  private static final long serialVersionUID = 0L;
+
   private final MetricMetadata metadata;
   private final Labels labels;
 
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/GaugeSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/GaugeSnapshot.java
index c94faf8dd..795323271 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/GaugeSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/GaugeSnapshot.java
@@ -5,7 +5,7 @@
 import java.util.List;
 
 /** Immutable snapshot of a Gauge. */
-public final class GaugeSnapshot extends MetricSnapshot {
+public final class GaugeSnapshot extends MetricSnapshot<GaugeSnapshot.GaugeDataPointSnapshot> {
 
   /**
    * To create a new {@link GaugeSnapshot}, you can either call the constructor directly or use the
@@ -20,7 +20,7 @@ public GaugeSnapshot(MetricMetadata metadata, Collection<GaugeDataPointSnapshot>
 
   @Override
   public List<GaugeDataPointSnapshot> getDataPoints() {
-    return (List<GaugeDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static final class GaugeDataPointSnapshot extends DataPointSnapshot {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/HistogramSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/HistogramSnapshot.java
index 5988cce3d..6966552a7 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/HistogramSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/HistogramSnapshot.java
@@ -5,7 +5,8 @@
 import java.util.List;
 
 /** Immutable snapshot of a Histogram. */
-public final class HistogramSnapshot extends MetricSnapshot {
+public final class HistogramSnapshot
+    extends MetricSnapshot<HistogramSnapshot.HistogramDataPointSnapshot> {
 
   private final boolean gaugeHistogram;
   public static final int CLASSIC_HISTOGRAM = Integer.MIN_VALUE;
@@ -41,7 +42,7 @@ public boolean isGaugeHistogram() {
 
   @Override
   public List<HistogramDataPointSnapshot> getDataPoints() {
-    return (List<HistogramDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static final class HistogramDataPointSnapshot extends DistributionDataPointSnapshot {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java
index c7f180d9f..ec8ece23c 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java
@@ -5,7 +5,7 @@
 import java.util.List;
 
 /** Immutable snapshot of an Info metric. */
-public final class InfoSnapshot extends MetricSnapshot {
+public final class InfoSnapshot extends MetricSnapshot<InfoSnapshot.InfoDataPointSnapshot> {
 
   /**
    * To create a new {@link InfoSnapshot}, you can either call the constructor directly or use the
@@ -24,7 +24,7 @@ public InfoSnapshot(MetricMetadata metadata, Collection<InfoDataPointSnapshot> d
 
   @Override
   public List<InfoDataPointSnapshot> getDataPoints() {
-    return (List<InfoDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static class InfoDataPointSnapshot extends DataPointSnapshot {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java
index d44e54ff9..420feeced 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java
@@ -1,24 +1,18 @@
 package io.prometheus.metrics.model.snapshots;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
 /** Base class for metric snapshots. */
-public abstract class MetricSnapshot {
+public abstract class MetricSnapshot<T extends DataPointSnapshot> {
 
   private final MetricMetadata metadata;
-  protected final List<? extends DataPointSnapshot> dataPoints;
+  protected final List<T> dataPoints;
 
-  protected MetricSnapshot(MetricMetadata metadata, DataPointSnapshot... dataPoints) {
-    this(metadata, Arrays.asList(dataPoints));
-  }
-
-  protected MetricSnapshot(
-      MetricMetadata metadata, Collection<? extends DataPointSnapshot> dataPoints) {
+  protected MetricSnapshot(MetricMetadata metadata, Collection<T> dataPoints) {
     if (metadata == null) {
       throw new NullPointerException("metadata");
     }
@@ -26,7 +20,7 @@ protected MetricSnapshot(
       throw new NullPointerException("dataPoints");
     }
     this.metadata = metadata;
-    List<? extends DataPointSnapshot> dataCopy = new ArrayList<>(dataPoints);
+    List<T> dataCopy = new ArrayList<>(dataPoints);
     dataCopy.sort(Comparator.comparing(DataPointSnapshot::getLabels));
     this.dataPoints = Collections.unmodifiableList(dataCopy);
     validateLabels();
@@ -36,7 +30,7 @@ public MetricMetadata getMetadata() {
     return metadata;
   }
 
-  public abstract List<? extends DataPointSnapshot> getDataPoints();
+  public abstract List<T> getDataPoints();
 
   protected void validateLabels() {
     // Verify that labels are unique (the same set of names/values must not be used multiple times
@@ -76,7 +70,7 @@ public T unit(Unit unit) {
       return self();
     }
 
-    public abstract MetricSnapshot build();
+    public abstract MetricSnapshot<?> build();
 
     protected MetricMetadata buildMetadata() {
       return new MetricMetadata(name, help, unit);
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java
index ecee897e4..f56976e9e 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java
@@ -14,12 +14,12 @@
 import java.util.stream.Stream;
 
 /** Immutable list of metric snapshots. */
-public class MetricSnapshots implements Iterable<MetricSnapshot> {
+public class MetricSnapshots implements Iterable<MetricSnapshot<?>> {
 
-  private final List<MetricSnapshot> snapshots;
+  private final List<MetricSnapshot<?>> snapshots;
 
   /** See {@link #MetricSnapshots(Collection)} */
-  public MetricSnapshots(MetricSnapshot... snapshots) {
+  public MetricSnapshots(MetricSnapshot<?>... snapshots) {
     this(Arrays.asList(snapshots));
   }
 
@@ -33,8 +33,8 @@ public MetricSnapshots(MetricSnapshot... snapshots) {
    *     Builder#containsMetricName(String)} before calling {@link
    *     Builder#metricSnapshot(MetricSnapshot)}.
    */
-  public MetricSnapshots(Collection<MetricSnapshot> snapshots) {
-    List<MetricSnapshot> list = new ArrayList<>(snapshots);
+  public MetricSnapshots(Collection<MetricSnapshot<?>> snapshots) {
+    List<MetricSnapshot<?>> list = new ArrayList<>(snapshots);
     list.sort(comparing(s -> s.getMetadata().getPrometheusName()));
     for (int i = 0; i < snapshots.size() - 1; i++) {
       if (list.get(i)
@@ -48,12 +48,12 @@ public MetricSnapshots(Collection<MetricSnapshot> snapshots) {
     this.snapshots = unmodifiableList(list);
   }
 
-  public static MetricSnapshots of(MetricSnapshot... snapshots) {
+  public static MetricSnapshots of(MetricSnapshot<?>... snapshots) {
     return new MetricSnapshots(snapshots);
   }
 
   @Override
-  public Iterator<MetricSnapshot> iterator() {
+  public Iterator<MetricSnapshot<?>> iterator() {
     return snapshots.iterator();
   }
 
@@ -61,11 +61,11 @@ public int size() {
     return snapshots.size();
   }
 
-  public MetricSnapshot get(int i) {
+  public MetricSnapshot<?> get(int i) {
     return snapshots.get(i);
   }
 
-  public Stream<MetricSnapshot> stream() {
+  public Stream<MetricSnapshot<?>> stream() {
     return snapshots.stream();
   }
 
@@ -75,7 +75,7 @@ public static Builder builder() {
 
   public static class Builder {
 
-    private final List<MetricSnapshot> snapshots = new ArrayList<>();
+    private final List<MetricSnapshot<?>> snapshots = new ArrayList<>();
     private final Set<String> prometheusNames = new HashSet<>();
 
     private Builder() {}
@@ -89,7 +89,7 @@ public boolean containsMetricName(String name) {
     }
 
     /** Add a metric snapshot. Call multiple times to add multiple metric snapshots. */
-    public Builder metricSnapshot(MetricSnapshot snapshot) {
+    public Builder metricSnapshot(MetricSnapshot<?> snapshot) {
       snapshots.add(snapshot);
       prometheusNames.add(snapshot.getMetadata().getPrometheusName());
       return this;
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java
index 591732137..7c6e49d19 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java
@@ -9,7 +9,8 @@
 import java.util.stream.Stream;
 
 /** Immutable snapshot of a StateSet metric. */
-public final class StateSetSnapshot extends MetricSnapshot {
+public final class StateSetSnapshot
+    extends MetricSnapshot<StateSetSnapshot.StateSetDataPointSnapshot> {
 
   /**
    * To create a new {@link StateSetSnapshot}, you can either call the constructor directly or use
@@ -37,7 +38,7 @@ private void validate() {
 
   @Override
   public List<StateSetDataPointSnapshot> getDataPoints() {
-    return (List<StateSetDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static class StateSetDataPointSnapshot extends DataPointSnapshot
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/SummarySnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/SummarySnapshot.java
index 7bc575ef8..26bd0f602 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/SummarySnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/SummarySnapshot.java
@@ -5,7 +5,8 @@
 import java.util.List;
 
 /** Immutable snapshot of a Summary metric. */
-public final class SummarySnapshot extends MetricSnapshot {
+public final class SummarySnapshot
+    extends MetricSnapshot<SummarySnapshot.SummaryDataPointSnapshot> {
 
   /**
    * To create a new {@link SummarySnapshot}, you can either call the constructor directly or use
@@ -20,7 +21,7 @@ public SummarySnapshot(MetricMetadata metadata, Collection<SummaryDataPointSnaps
 
   @Override
   public List<SummaryDataPointSnapshot> getDataPoints() {
-    return (List<SummaryDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static final class SummaryDataPointSnapshot extends DistributionDataPointSnapshot {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/UnknownSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/UnknownSnapshot.java
index 3fe01c9df..30ec564cb 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/UnknownSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/UnknownSnapshot.java
@@ -5,7 +5,8 @@
 import java.util.List;
 
 /** Immutable snapshot of an Unknown (Untyped) metric. */
-public final class UnknownSnapshot extends MetricSnapshot {
+public final class UnknownSnapshot
+    extends MetricSnapshot<UnknownSnapshot.UnknownDataPointSnapshot> {
 
   /**
    * To create a new {@link UnknownSnapshot}, you can either call the constructor directly or use
@@ -21,7 +22,7 @@ public UnknownSnapshot(MetricMetadata metadata, Collection<UnknownDataPointSnaps
 
   @Override
   public List<UnknownDataPointSnapshot> getDataPoints() {
-    return (List<UnknownDataPointSnapshot>) dataPoints;
+    return dataPoints;
   }
 
   public static final class UnknownDataPointSnapshot extends DataPointSnapshot {
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java
index 55e8b0be4..6557c0ecf 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java
@@ -19,7 +19,7 @@ class PrometheusRegistryTest {
   Collector counterA1 =
       new Collector() {
         @Override
-        public MetricSnapshot collect() {
+        public MetricSnapshot<?> collect() {
           return CounterSnapshot.builder().name("counter_a").build();
         }
 
@@ -32,7 +32,7 @@ public String getPrometheusName() {
   Collector counterA2 =
       new Collector() {
         @Override
-        public MetricSnapshot collect() {
+        public MetricSnapshot<?> collect() {
           return CounterSnapshot.builder().name("counter.a").build();
         }
 
@@ -45,7 +45,7 @@ public String getPrometheusName() {
   Collector counterB =
       new Collector() {
         @Override
-        public MetricSnapshot collect() {
+        public MetricSnapshot<?> collect() {
           return CounterSnapshot.builder().name("counter_b").build();
         }
 
@@ -58,7 +58,7 @@ public String getPrometheusName() {
   Collector gaugeA =
       new Collector() {
         @Override
-        public MetricSnapshot collect() {
+        public MetricSnapshot<?> collect() {
           return GaugeSnapshot.builder().name("gauge_a").build();
         }
 
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotTest.java
index fc0c24bfc..25cd6a4ec 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotTest.java
@@ -34,7 +34,7 @@ public void testDuplicateLabels() {
 
   @Test
   public void testNoData() {
-    MetricSnapshot snapshot = CounterSnapshot.builder().name("test").build();
+    MetricSnapshot<?> snapshot = CounterSnapshot.builder().name("test").build();
     assertThat(snapshot.getDataPoints().size()).isEqualTo(0);
   }
 
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotsTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotsTest.java
index ed2f66fec..09d63d4d9 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotsTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricSnapshotsTest.java
@@ -92,7 +92,7 @@ public void testImmutable() {
             .dataPoint(CounterSnapshot.CounterDataPointSnapshot.builder().value(1.0).build())
             .build();
     MetricSnapshots snapshots = new MetricSnapshots(c2, c3, c1);
-    Iterator<MetricSnapshot> iterator = snapshots.iterator();
+    Iterator<MetricSnapshot<?>> iterator = snapshots.iterator();
     iterator.next();
     assertThatExceptionOfType(UnsupportedOperationException.class).isThrownBy(iterator::remove);
   }
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/SnapshotTestUtil.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/SnapshotTestUtil.java
index d8e8d33e4..a69bba499 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/SnapshotTestUtil.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/SnapshotTestUtil.java
@@ -5,7 +5,7 @@
 class SnapshotTestUtil {
 
   public static void assertMetadata(
-      MetricSnapshot snapshot, String name, String help, String unit) {
+      MetricSnapshot<?> snapshot, String name, String help, String unit) {
     assertThat(snapshot.getMetadata().getName()).isEqualTo(name);
     assertThat(snapshot.getMetadata().getHelp()).isEqualTo(help);
     if (unit != null) {
diff --git a/prometheus-metrics-simpleclient-bridge/src/main/java/io/prometheus/metrics/simpleclient/bridge/SimpleclientCollector.java b/prometheus-metrics-simpleclient-bridge/src/main/java/io/prometheus/metrics/simpleclient/bridge/SimpleclientCollector.java
index f1b592eaa..e68ebd968 100644
--- a/prometheus-metrics-simpleclient-bridge/src/main/java/io/prometheus/metrics/simpleclient/bridge/SimpleclientCollector.java
+++ b/prometheus-metrics-simpleclient-bridge/src/main/java/io/prometheus/metrics/simpleclient/bridge/SimpleclientCollector.java
@@ -101,7 +101,7 @@ private MetricSnapshots convert(Enumeration<Collector.MetricFamilySamples> sampl
     return result.build();
   }
 
-  private MetricSnapshot convertCounter(Collector.MetricFamilySamples samples) {
+  private MetricSnapshot<?> convertCounter(Collector.MetricFamilySamples samples) {
     CounterSnapshot.Builder counter =
         CounterSnapshot.builder()
             .name(sanitizeMetricName(samples.name))
@@ -128,7 +128,7 @@ private MetricSnapshot convertCounter(Collector.MetricFamilySamples samples) {
     return counter.build();
   }
 
-  private MetricSnapshot convertGauge(Collector.MetricFamilySamples samples) {
+  private MetricSnapshot<?> convertGauge(Collector.MetricFamilySamples samples) {
     GaugeSnapshot.Builder gauge =
         GaugeSnapshot.builder()
             .name(sanitizeMetricName(samples.name))
@@ -148,7 +148,7 @@ private MetricSnapshot convertGauge(Collector.MetricFamilySamples samples) {
     return gauge.build();
   }
 
-  private MetricSnapshot convertHistogram(
+  private MetricSnapshot<?> convertHistogram(
       Collector.MetricFamilySamples samples, boolean isGaugeHistogram) {
     HistogramSnapshot.Builder histogram =
         HistogramSnapshot.builder()
@@ -192,7 +192,7 @@ private MetricSnapshot convertHistogram(
     return histogram.build();
   }
 
-  private MetricSnapshot convertSummary(Collector.MetricFamilySamples samples) {
+  private MetricSnapshot<?> convertSummary(Collector.MetricFamilySamples samples) {
     SummarySnapshot.Builder summary =
         SummarySnapshot.builder()
             .name(sanitizeMetricName(samples.name))
@@ -242,7 +242,7 @@ private MetricSnapshot convertSummary(Collector.MetricFamilySamples samples) {
     return summary.build();
   }
 
-  private MetricSnapshot convertStateSet(Collector.MetricFamilySamples samples) {
+  private MetricSnapshot<?> convertStateSet(Collector.MetricFamilySamples samples) {
     StateSetSnapshot.Builder stateSet =
         StateSetSnapshot.builder().name(sanitizeMetricName(samples.name)).help(samples.help);
     Map<Labels, StateSetSnapshot.StateSetDataPointSnapshot.Builder> dataPoints = new HashMap<>();
@@ -271,7 +271,7 @@ private MetricSnapshot convertStateSet(Collector.MetricFamilySamples samples) {
     return stateSet.build();
   }
 
-  private MetricSnapshot convertUnknown(Collector.MetricFamilySamples samples) {
+  private MetricSnapshot<?> convertUnknown(Collector.MetricFamilySamples samples) {
     UnknownSnapshot.Builder unknown =
         UnknownSnapshot.builder()
             .name(sanitizeMetricName(samples.name))
@@ -353,7 +353,7 @@ private Labels labelsWithout(
     return labels.build();
   }
 
-  private MetricSnapshot convertInfo(Collector.MetricFamilySamples samples) {
+  private MetricSnapshot<?> convertInfo(Collector.MetricFamilySamples samples) {
     InfoSnapshot.Builder info =
         InfoSnapshot.builder().name(sanitizeMetricName(samples.name)).help(samples.help);
     for (Collector.MetricFamilySamples.Sample sample : samples.samples) {