diff --git a/zephyr-env.sh b/zephyr-env.sh
index dcb0638b72d..980ee93e915 100644
--- a/zephyr-env.sh
+++ b/zephyr-env.sh
@@ -1,5 +1,5 @@
 
-if [ "X$(basename -- "$0")" == "Xzephyr-env.sh" ]; then
+if [ "X$(basename -z -- "$0")" "==" "Xzephyr-env.sh" ]; then
     echo "Source this file (do NOT execute it!) to set the Zephyr Kernel environment."
     exit
 fi