diff --git a/bin/release b/bin/release
index fd3711e..df18137 100755
--- a/bin/release
+++ b/bin/release
@@ -5,6 +5,7 @@ VERSION_FILE=socketio/__init__.py
 
 if [[ "$VERSION" == "" ]]; then
     echo "Usage: $0 <version>"
+    exit 1
 fi
 
 # update change log