diff --git a/ext/mbstring/mbstring.c b/ext/mbstring/mbstring.c
index 719c62b7277..62d26fa2615 100644
--- a/ext/mbstring/mbstring.c
+++ b/ext/mbstring/mbstring.c
@@ -3227,7 +3227,7 @@ PHP_FUNCTION(mb_detect_encoding)
 	}
 
 	if (ret == NULL) {
-		RETVAL_FALSE;
+		RETURN_FALSE;
 	}
 
 	RETVAL_STRING((char *)ret, 1);