diff --git a/.github/workflows/verify.yml b/.github/workflows/verify.yml
index 4693ffe..cc7ea70 100644
--- a/.github/workflows/verify.yml
+++ b/.github/workflows/verify.yml
@@ -18,7 +18,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: '21'
+          java-version: '8'
 
       - name: Assemble
         run: ./gradlew :jme3-testdata:assemble --console=plain --stacktrace
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index c61a118..aaaabb3 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-9.4.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.4-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/jme3-testdata/build.gradle b/jme3-testdata/build.gradle
index 4c21f82..8b21ded 100644
--- a/jme3-testdata/build.gradle
+++ b/jme3-testdata/build.gradle
@@ -5,6 +5,11 @@ apply plugin: 'java-library'
 apply plugin: 'maven-publish'
 apply plugin: 'signing'
 
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 group = 'org.jmonkeyengine'
 version = rootProject.version