diff --git a/metadata/de.syss.MifareClassicTool.yml b/metadata/de.syss.MifareClassicTool.yml
index 43092bde7d..e526660a6f 100644
--- a/metadata/de.syss.MifareClassicTool.yml
+++ b/metadata/de.syss.MifareClassicTool.yml
@@ -433,7 +433,20 @@ Builds:
     rm:
       - tools
 
+  - versionName: 4.2.1
+    versionCode: 66
+    commit: 9336861081d73922f65b0f4859fb2b04e7b2f289
+    subdir: Mifare Classic Tool/app
+    sudo:
+      - apt-get update
+      - apt-get install -y openjdk-17-jdk-headless
+      - update-java-alternatives -a
+    gradle:
+      - yes
+    rm:
+      - tools
+
 AutoUpdateMode: Version
 UpdateCheckMode: Tags
-CurrentVersion: 4.2.0
-CurrentVersionCode: 65
+CurrentVersion: 4.2.1
+CurrentVersionCode: 66