1 files changed, 1 insertions, 1 deletions
diff --git a/tools/run-centos b/tools/run-centos
index b10e3bc4..d44d5145 100755
--- a/tools/run-centos
+++ b/tools/run-centos
@@ -262,7 +262,7 @@ main() {
     return 0
 }
 
-if [ "$1" = "prep" ]; then
+if [ "${1:-}" = "prep" ]; then
     shift
     prep "$@"
 else