diff --git a/test-scripts/install_k8s.sh b/test-scripts/install_k8s.sh
index 68b48d2..b9af7da 100644
--- a/test-scripts/install_k8s.sh
+++ b/test-scripts/install_k8s.sh
@@ -17,7 +17,7 @@ usage() {
   echo "Usage: $0 -i IP -a ACTION"
   echo "Required arguments:"
   echo "  -i, --ip IP           Specify the IP address"
-  echo "  -a, --action ACTION   Specify the action to perform"
+  echo "  -prune, --prune true/false true to overwrite existing cluster"
   echo "Optional arguments:"
   echo "  -h, --help            Show this help message and exit"
   exit 1