diff --git a/.gitea/workflows/back.yaml b/.gitea/workflows/back.yaml
index f68f425..91ffdd3 100644
--- a/.gitea/workflows/back.yaml
+++ b/.gitea/workflows/back.yaml
@@ -8,6 +8,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4 # v2 minimum required
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin' # See 'Supported distributions' for available options
+          java-version: '21'
       - uses: axel-op/googlejavaformat-action@v3
         with:
           args: "--replace"