diff --git a/.editorconfig b/.editorconfig
index a9a165bae..6ef5d690a 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -12,6 +12,9 @@ end_of_line = lf
 [{*.bat,*.cmd}]
 end_of_line = crlf
 
+[{*.mustache,*.ftl}]
+insert_final_newline = false
+
 [*.java]
 indent_size = 4
 tab_width = 4
diff --git a/.github/workflows/graalvm-latest.yml b/.github/workflows/graalvm-latest.yml
index bfbfff345..d150aa606 100644
--- a/.github/workflows/graalvm-latest.yml
+++ b/.github/workflows/graalvm-latest.yml
@@ -34,7 +34,9 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       max-parallel: 6
-      matrix: ${{ fromJson(needs.build_matrix.outputs.matrix) }}
+      matrix:
+        java: ['17', '21']
+        native_test_task: ${{ fromJson(needs.build_matrix.outputs.matrix).native_test_task }}
     env:
       GRADLE_ENTERPRISE_ACCESS_KEY: ${{ secrets.GRADLE_ENTERPRISE_ACCESS_KEY }}
       GRADLE_ENTERPRISE_CACHE_USERNAME: ${{ secrets.GRADLE_ENTERPRISE_CACHE_USERNAME }}
@@ -46,7 +48,7 @@ jobs:
         id: pre-build
         with:
           distribution: 'graalvm'
-          java: '17'
+          java: ${{ matrix.java }}
       - name: Build Steps
         uses: micronaut-projects/github-actions/graalvm/build@master
         id: build
@@ -60,4 +62,4 @@ jobs:
         uses: micronaut-projects/github-actions/graalvm/post-build@master
         id: post-build
         with:
-          java: '17'
+          java: ${{ matrix.java }}
diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index f60182451..7c0d4941b 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: ['17']
+        java: ['17', '21']
     env:
       GRADLE_ENTERPRISE_ACCESS_KEY: ${{ secrets.GRADLE_ENTERPRISE_ACCESS_KEY }}
       GRADLE_ENTERPRISE_CACHE_USERNAME: ${{ secrets.GRADLE_ENTERPRISE_CACHE_USERNAME }}
@@ -64,7 +64,7 @@ jobs:
           ./gradlew check --no-daemon --continue
 
       - name: "🔎 Run static analysis"
-        if: env.SONAR_TOKEN != ''
+        if: env.SONAR_TOKEN != '' && matrix.java == '17'
         run: |
           ./gradlew sonar
 
diff --git a/gradle.properties b/gradle.properties
index 66ebaaa13..70217b0aa 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -7,7 +7,6 @@ projectUrl=https://micronaut.io
 githubSlug=micronaut-projects/micronaut-kafka
 developers=Graeme Rocher
 
-
 testskafka=kafka/src/test/groovy/io/micronaut/configuration/kafka/docs
 testskafkastreams=kafka-streams/src/test/groovy/io/micronaut/configuration/kafka/streams
 kafkastreams=kafka-streams/src/main/java/io/micronaut/configuration/kafka/streams
@@ -17,3 +16,17 @@ org.gradle.caching=true
 org.gradle.jvmargs=-Xmx2048M
 org.gradle.parallel=true
 org.gradle.daemon=true
+
+# No matter which Java toolchain we use, the Kotlin Daemon is always invoked by the current JDK.
+# Therefor to fix Kapt errors when running tests under Java 21, we need to open up some modules for the Kotlin Daemon.
+kotlin.daemon.jvmargs=--add-opens=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED\
+ --add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED \
+ --add-opens=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
+
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 033e24c4c..7f93135c4 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index ac72c34e8..3fa8f862f 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
index fcb6fca14..1aa94a426 100755
--- a/gradlew
+++ b/gradlew
@@ -83,7 +83,8 @@ done
 # This is normally unused
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -144,7 +145,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
@@ -152,7 +153,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -201,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
diff --git a/settings.gradle b/settings.gradle
index b9d88fc2c..02542b330 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -6,7 +6,7 @@ pluginManagement {
 }
 
 plugins {
-    id("io.micronaut.build.shared.settings") version "6.5.6"
+    id("io.micronaut.build.shared.settings") version "6.6.0"
 }
 
 enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS")
diff --git a/test-suite-kotlin/build.gradle.kts b/test-suite-kotlin/build.gradle.kts
index 1f1a6e8f5..6a5be313d 100644
--- a/test-suite-kotlin/build.gradle.kts
+++ b/test-suite-kotlin/build.gradle.kts
@@ -10,3 +10,9 @@ dependencies {
     testImplementation(mnTest.micronaut.test.junit5)
     testImplementation(libs.kotlinx.coroutines)
 }
+
+kotlin {
+    jvmToolchain {
+        languageVersion.set(JavaLanguageVersion.of(17))
+    }
+}