diff --git a/ext/json/tests/gh15168.phpt b/ext/json/tests/gh15168.phpt
index 90844ae0ff2..9b674d6b4ac 100644
--- a/ext/json/tests/gh15168.phpt
+++ b/ext/json/tests/gh15168.phpt
@@ -5,7 +5,7 @@ GH-15168 (stack overflow in json_encode())
 if (ini_get('zend.max_allowed_stack_size') === false) {
     die('skip No stack limit support');
 }
-if (getenv('SKIP_ASAN)) {
+if (getenv('SKIP_ASAN')) {
     die('skip ASAN needs different stack limit setting due to more stack space usage');
 }
 ?>