diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index 501f527..c78631a 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -20,10 +20,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-    - name: Set up JDK 11
+    - name: Set up JDK 21
       uses: actions/setup-java@v4
       with:
-        java-version: '11'
+        java-version: '21'
         distribution: 'temurin'
         cache: 'gradle'
     - name: Build with Gradle
diff --git a/.idea/kotlinc.xml b/.idea/kotlinc.xml
index 6d0ee1c..d4b7acc 100644
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="KotlinJpsPluginSettings">
-    <option name="version" value="2.0.0" />
+    <option name="version" value="2.0.20" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index b3878b2..0895684 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -14,11 +14,11 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="temurin-11" project-jdk-type="JavaSDK" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="temurin-21" project-jdk-type="JavaSDK" />
   <component name="ProjectType">
     <option name="id" value="jpab" />
   </component>
   <component name="SuppressKotlinCodeStyleNotification">
     <option name="disableForAll" value="true" />
   </component>
-</project>
+</project>
\ No newline at end of file
diff --git a/.java-version b/.java-version
index b4de394..aabe6ec 100644
--- a/.java-version
+++ b/.java-version
@@ -1 +1 @@
-11
+21
diff --git a/build.gradle.kts b/build.gradle.kts
index a3f00e6..d03c089 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -21,7 +21,7 @@ subprojects {
 
     tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().all {
         kotlinOptions {
-            jvmTarget = JavaVersion.VERSION_11.toString()
+            jvmTarget = JavaVersion.VERSION_21.toString()
         }
     }
 
diff --git a/docs/global/modules/samples/pages/index.adoc b/docs/global/modules/samples/pages/index.adoc
index 94209f0..9ac8182 100644
--- a/docs/global/modules/samples/pages/index.adoc
+++ b/docs/global/modules/samples/pages/index.adoc
@@ -15,7 +15,7 @@ The purpose of the examples is to give inspiration for what is possible with mod
 To work with the samples, you need the following software installed.:
 
 * MPS `2021.2.6`
-* Java 11
+* Java 21
 * Docker and https://docs.docker.com/compose/[Docker Compose]
 +
 Alternatives like https://podman.io/[Podman] might work, but have not been tested.
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 1baf2bb..22598f5 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -28,7 +28,7 @@ quarkusPlatform = "2.16.12.Final"
 quarkusPlugin = "2.16.12.Final"
 
 # other
-openapi = "7.5.0"
+openapi = "7.8.0"
 kotlin = "2.0.20"
 antJunit = "1.10.15"
 junit = "4.13.2"
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 249e583..ccebba7 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 e1bef7e..5c40527 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.0.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10.2-bin.zip
+networkTimeout=10000
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index a69d9cb..79a61d4 100755
--- a/gradlew
+++ b/gradlew
@@ -55,7 +55,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -80,10 +80,10 @@ do
     esac
 done
 
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-APP_NAME="Gradle"
+# This is normally unused
+# shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
 
 # 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"'
@@ -143,12 +143,16 @@ fi
 if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
diff --git a/gradlew.bat b/gradlew.bat
index f127cfd..93e3f59 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -26,6 +26,7 @@ if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
 if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
diff --git a/rest-api-model-server/build.gradle.kts b/rest-api-model-server/build.gradle.kts
index 46c5a68..6764403 100644
--- a/rest-api-model-server/build.gradle.kts
+++ b/rest-api-model-server/build.gradle.kts
@@ -82,8 +82,8 @@ tasks.named("compileKotlin") {
 }
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_11
-    targetCompatibility = JavaVersion.VERSION_11
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
 }
 
 java.sourceSets.getByName("main").java.srcDir(file("$buildDir/openapi-generator/src/main/kotlin"))
@@ -98,6 +98,6 @@ allOpen {
 }
 
 tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
-    kotlinOptions.jvmTarget = JavaVersion.VERSION_11.toString()
+    kotlinOptions.jvmTarget = JavaVersion.VERSION_21.toString()
     kotlinOptions.javaParameters = true
 }