diff --git a/build-tools/sign-rpms b/build-tools/sign-rpms
index f0512e9f..403d1eab 100755
--- a/build-tools/sign-rpms
+++ b/build-tools/sign-rpms
@@ -279,7 +279,7 @@ check_vars
 echo signing $_PKG_DIR
 
 # sign all rpms
-if [ "$USER" == "jenkins" ]; then
+if [ "$USER" == "jenkins" ] && [ ! -z "${SIGNING_USER}" ] && [ ! -z "${SIGNING_SERVER}" ] && [ ! -z "${SIGNING_SERVER_SCRIPT}" ]; then
     sign_packages_on_server
     retval=$?
 else