diff --git a/ci/Jenkinsfile b/ci/Jenkinsfile
index 8315aa6..286f108 100644
--- a/ci/Jenkinsfile
+++ b/ci/Jenkinsfile
@@ -40,7 +40,7 @@ try {
         }
 
         stage('Sign') {
-            when(BRANCH_NAME == 'main') {
+            if (BRANCH_NAME == 'main') {
                 withEnvironment([
                     "GNUPGHOME=${env.WORKSPACE_TMP}/gnupg",
                 ]) {
@@ -57,6 +57,14 @@ try {
                         sh '. ci/sign.sh'
                     }
                 }
+            } else {
+                catchError(
+                    catchInterruptions: false, 
+                    buildResult: null,
+                    stageResult: 'NOT_BUILT',
+                ) {
+                    error('skip')
+                }
             }
         }