diff --git a/build.gradle b/build.gradle
index 79c007f6..31676d7c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -9,8 +9,6 @@ buildscript {
         // Note: Since Jackson 2.14, Android SDK 26 is required
         // https://github.com/FasterXML/jackson/wiki/Jackson-Releases
         jacksonVersion = '2.16.1' // https://github.com/FasterXML/jackson-databind/tags
-        // retrofit is why we need allow-opens. context: https://stackoverflow.com/questions/60915381/retrofit2-maven-project-illegal-reflective-access-warning // https://github.com/square/retrofit/issues/3341
-        //   Note that after Java 14, this isn't a problem, so I'm not inclined to keep having add-opens because of retrofit
         retrofitVersion = "2.9.0" // https://github.com/square/retrofit/tags
         shadowVersion = '8.1.1' // https://github.com/johnrengelman/shadow/releases
         ioLibVersion = '2.3.0' // https://github.com/retrodaredevil/io-lib/releases
diff --git a/client/build.gradle b/client/build.gradle
index c0ffb963..3121089e 100644
--- a/client/build.gradle
+++ b/client/build.gradle
@@ -3,8 +3,8 @@ plugins {
     id 'java'
 }
 
-sourceCompatibility = JavaVersion.VERSION_11
-targetCompatibility = JavaVersion.VERSION_11
+sourceCompatibility = JavaVersion.VERSION_17
+targetCompatibility = JavaVersion.VERSION_17
 
 version '0.0.1-SNAPSHOT'
 
diff --git a/common/build.gradle b/common/build.gradle
index eb552aa4..884d121e 100644
--- a/common/build.gradle
+++ b/common/build.gradle
@@ -2,8 +2,8 @@ plugins {
     id 'java'
 }
 
-sourceCompatibility = JavaVersion.VERSION_11
-targetCompatibility = JavaVersion.VERSION_11
+sourceCompatibility = JavaVersion.VERSION_17
+targetCompatibility = JavaVersion.VERSION_17
 
 version = '0.0.1-SNAPSHOT'
 
diff --git a/docker/solarthing-server/Dockerfile b/docker/solarthing-server/Dockerfile
index 63bd4302..82fa8747 100644
--- a/docker/solarthing-server/Dockerfile
+++ b/docker/solarthing-server/Dockerfile
@@ -1,10 +1,10 @@
-FROM eclipse-temurin:19-jre-jammy as builder
+FROM ghcr.io/retrodaredevil/lavender-jre:21-ubuntu-jammy as builder
 ARG JAR_LOCATION
 COPY ${JAR_LOCATION} application.jar
 RUN java -Djarmode=layertools -jar application.jar extract
 
 
-FROM eclipse-temurin:19-jre-jammy
+FROM ghcr.io/retrodaredevil/lavender-jre:21-ubuntu-jammy
 
 RUN ["mkdir", "/solarthing"]
 WORKDIR "/solarthing"
diff --git a/docker/solarthing/Dockerfile b/docker/solarthing/Dockerfile
index ad12b93f..940f128b 100644
--- a/docker/solarthing/Dockerfile
+++ b/docker/solarthing/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:19-jre-jammy
+FROM ghcr.io/retrodaredevil/lavender-jre:21-ubuntu-jammy
 ARG JAR_LOCATION
 ARG COMMIT_HASH=""
 ARG REF=""
@@ -11,8 +11,4 @@ ENV REF="$REF"
 
 RUN ["mkdir", "/app"]
 WORKDIR "/app"
-# Currently this entry point does not need any allow opens.
-#   The default raw_solarthing will run solarthing.jar with `--add-opens=java.base/java.lang.invoke=ALL-UNNAMED`
-#   Because Retrofit (https://stackoverflow.com/a/61259233/5434860)
-#   However, that bug/workaround only affects Java versions [9, 13], but we are running a higher Java version so we are unaffected.
 ENTRYPOINT ["java", "-XX:ErrorFile=/app/jvmlog/hs_err_pid%p.log", "-jar", "/solarthing/solarthing.jar"]
diff --git a/process-annotations/build.gradle b/process-annotations/build.gradle
index 0ced4633..f87af31c 100644
--- a/process-annotations/build.gradle
+++ b/process-annotations/build.gradle
@@ -2,8 +2,8 @@ plugins {
     id 'java'
 }
 
-sourceCompatibility = JavaVersion.VERSION_11
-targetCompatibility = JavaVersion.VERSION_11
+sourceCompatibility = JavaVersion.VERSION_17
+targetCompatibility = JavaVersion.VERSION_17
 
 version '0.0.1-SNAPSHOT'
 
diff --git a/program/.bin/raw_solarthing b/program/.bin/raw_solarthing
index 2bc0fa37..66663afc 100755
--- a/program/.bin/raw_solarthing
+++ b/program/.bin/raw_solarthing
@@ -2,10 +2,6 @@
 
 BASEDIR=$(dirname "$0")
 
-if java --add-opens 2>&1 | grep 'requires modules' >/dev/null; then
-  java --add-opens=java.base/java.lang.invoke=ALL-UNNAMED -jar "$BASEDIR/../solarthing.jar" "$@"
-else
-  java -jar "$BASEDIR/../solarthing.jar" "$@"
-fi
+java -jar "$BASEDIR/../solarthing.jar" "$@"
 # It is important that we do not have any more commands after this because we want the exit code
 #   to be the same as the exit code of the java command
diff --git a/program/graphql/run.sh b/program/graphql/run.sh
index 715aed5f..b3d044b8 100755
--- a/program/graphql/run.sh
+++ b/program/graphql/run.sh
@@ -9,8 +9,4 @@ cd "$BASEDIR" || exit 1
 export SOLARTHING_ROOT="../.."
 source ../.scripts/use_sdkman_if_available.sh # requires bash
 
-if java --add-opens 2>&1 | grep 'requires modules' >/dev/null; then
-  java --add-opens java.base/java.lang.reflect=ALL-UNNAMED --add-opens java.base/java.lang.invoke=ALL-UNNAMED -jar ../solarthing-graphql.jar --spring.config.location=config/application.properties
-else
-  java -jar ../solarthing-graphql.jar --spring.config.location=config/application.properties
-fi
+java -jar ../solarthing-graphql.jar --spring.config.location=config/application.properties
diff --git a/server/build.gradle b/server/build.gradle
index cb09fb99..e5b8f531 100644
--- a/server/build.gradle
+++ b/server/build.gradle
@@ -15,8 +15,8 @@ apply plugin: 'java'
 apply plugin: 'org.springframework.boot'
 apply plugin: 'io.spring.dependency-management'
 
-sourceCompatibility = JavaVersion.VERSION_17
-targetCompatibility = JavaVersion.VERSION_17
+sourceCompatibility = JavaVersion.VERSION_21
+targetCompatibility = JavaVersion.VERSION_21
 
 version = '0.0.1-SNAPSHOT'