diff --git a/tools/test-install/install b/tools/test-install/install
index 623c9a907e..3b81296c35 100755
--- a/tools/test-install/install
+++ b/tools/test-install/install
@@ -16,7 +16,7 @@ while true; do
         *) usage;;
     esac
 done
-INSTALLER="$1"; shift
+INSTALLER="$1"; shift || usage
 INSTALLER_ARGS=("$@"); set --
 
 if [ -z "$RELEASE" ] || [ -z "$INSTALLER" ]; then