diff --git a/generate-tarball.sh b/generate-tarball.sh
index 3970cba..cb93e2e 100755
--- a/generate-tarball.sh
+++ b/generate-tarball.sh
@@ -2,6 +2,12 @@
 
 VERSION=$1
 
+if [ -z "$VERSION" ]; then
+    echo >&2 "Usage:"
+    echo >&2 "    $0 <version>"
+    exit 1
+fi
+
 rm -rf mysql-connector-j-$VERSION
 wget https://github.com/mysql/mysql-connector-j/archive/$VERSION.tar.gz
 tar xfz $VERSION.tar.gz || exit 1
@@ -14,4 +20,4 @@ tar cfJ mysql-connector-java-$VERSION-nojars.tar.xz mysql-connector-j-$VERSION |
 
 rm -rf mysql-connector-j-$VERSION $VERSION.tar.gz
 
-exit 0
\ No newline at end of file
+exit 0