diff --git a/.gitea/workflows/test_build.yml b/.gitea/workflows/test_build.yml
index ae070cd..e74e123 100644
--- a/.gitea/workflows/test_build.yml
+++ b/.gitea/workflows/test_build.yml
@@ -14,7 +14,8 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: '17'
-      - name: Validate Gradle Wrapper
-        uses: gradle/actions/wrapper-validation@v3
+      - name: Validate Gradle Wrapper (offline checksum)
+        run: |
+          sha256sum --check gradle/wrapper/gradle-wrapper.jar.sha256
       - name: Gradle build
         run: ./gradlew build --info
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.jar.sha256 b/gradle/wrapper/gradle-wrapper.jar.sha256
new file mode 100644
index 0000000..fdb15aa
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.jar.sha256
@@ -0,0 +1 @@
+81a82aaea5abcc8ff68b3dfcb58b3c3c429378efd98e7433460610fecd7ae45f  gradle/wrapper/gradle-wrapper.jar