diff --git a/install-plugins.sh b/install-plugins.sh
index 4ea9cf5..722fb3f 100755
--- a/install-plugins.sh
+++ b/install-plugins.sh
@@ -62,9 +62,7 @@
         return 0
     fi
 
-    if [ -z "$JENKINS_UC_DOWNLOAD" ]; then
-      JENKINS_UC_DOWNLOAD=$JENKINS_UC/download
-    fi
+    JENKINS_UC_DOWNLOAD=${JENKINS_UC_DOWNLOAD=-"$JENKINS_UC/download"}
 
     url="$JENKINS_UC_DOWNLOAD/plugins/$plugin/$version/${plugin}.hpi"