diff --git a/implementations/micrometer-registry-signalfx/src/main/java/io/micrometer/signalfx/SignalFxNamingConvention.java b/implementations/micrometer-registry-signalfx/src/main/java/io/micrometer/signalfx/SignalFxNamingConvention.java
index 1e6e441a92..7429a4237d 100644
--- a/implementations/micrometer-registry-signalfx/src/main/java/io/micrometer/signalfx/SignalFxNamingConvention.java
+++ b/implementations/micrometer-registry-signalfx/src/main/java/io/micrometer/signalfx/SignalFxNamingConvention.java
@@ -22,17 +22,25 @@
 import io.micrometer.core.instrument.util.StringEscapeUtils;
 import io.micrometer.core.instrument.util.StringUtils;
 import io.micrometer.core.lang.Nullable;
+import io.micrometer.core.util.internal.logging.WarnThenDebugLogger;
 
 /**
- * See https://developers.signalfx.com/reference#section-criteria-for-metric-and-dimension-names-and-values for criteria.
+ * {@link NamingConvention} for SignalFx.
+ *
+ * See https://developers.signalfx.com/metrics/data_ingest_overview.html#_criteria_for_metric_and_dimension_names_and_values
  *
  * @author Jon Schneider
+ * @author Johnny Lim
  */
 public class SignalFxNamingConvention implements NamingConvention {
 
+    private static final WarnThenDebugLogger logger = new WarnThenDebugLogger(SignalFxNamingConvention.class);
+
     private static final Pattern START_UNDERSCORE_PATTERN = Pattern.compile("^_");
     private static final Pattern SF_PATTERN = Pattern.compile("^sf_");
     private static final Pattern START_LETTERS_PATTERN = Pattern.compile("^[a-zA-Z].*");
+    private static final Pattern PATTERN_TAG_KEY_BLACKLISTED_CHARS = Pattern.compile("[^\\w_\\-]");
+    private static final Pattern PATTERN_TAG_KEY_BLACKLISTED_PREFIX = Pattern.compile("^(aws|gcp|azure)_.*");
 
     private static final int NAME_MAX_LENGTH = 256;
     private static final int TAG_VALUE_MAX_LENGTH = 256;
@@ -66,9 +74,16 @@ public String tagKey(String key) {
         conventionKey = START_UNDERSCORE_PATTERN.matcher(conventionKey).replaceAll(""); // 2
         conventionKey = SF_PATTERN.matcher(conventionKey).replaceAll(""); // 2
 
+        conventionKey = PATTERN_TAG_KEY_BLACKLISTED_CHARS.matcher(conventionKey).replaceAll("_");
         if (!START_LETTERS_PATTERN.matcher(conventionKey).matches()) { // 3
             conventionKey = "a" + conventionKey;
         }
+        if (PATTERN_TAG_KEY_BLACKLISTED_PREFIX.matcher(conventionKey).matches()) {
+            logger.log("'" + conventionKey + "' (original name: '" + key + "') is not a valid tag key. "
+                    + "Must not start with any of these prefixes: aws_, gcp_, or azure_. "
+                    + "Please rename it to conform to the constraints. "
+                    + "If it comes from a third party, please use MeterFilter to rename it.");
+        }
         return StringUtils.truncate(conventionKey, KEY_MAX_LENGTH); // 1
     }
 
diff --git a/implementations/micrometer-registry-signalfx/src/test/java/io/micrometer/signalfx/SignalFxNamingConventionTest.java b/implementations/micrometer-registry-signalfx/src/test/java/io/micrometer/signalfx/SignalFxNamingConventionTest.java
index 0e2b332577..706e959323 100644
--- a/implementations/micrometer-registry-signalfx/src/test/java/io/micrometer/signalfx/SignalFxNamingConventionTest.java
+++ b/implementations/micrometer-registry-signalfx/src/test/java/io/micrometer/signalfx/SignalFxNamingConventionTest.java
@@ -19,6 +19,12 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+/**
+ * Tests for {@link SignalFxNamingConvention}.
+ *
+ * @author Jon Schneider
+ * @author Johnny Lim
+ */
 class SignalFxNamingConventionTest {
     private SignalFxNamingConvention convention = new SignalFxNamingConvention();
 
@@ -30,4 +36,9 @@ void tagKey() {
         assertThat(convention.tagKey("123")).isEqualTo("a123");
     }
 
-}
\ No newline at end of file
+    @Test
+    void tagKeyWhenKeyHasBlacklistedCharShouldSanitize() {
+        assertThat(convention.tagKey("a.b")).isEqualTo("a_b");
+    }
+
+}