diff --git a/ext/standard/basic_functions.c b/ext/standard/basic_functions.c
index 7f15e808523..44f61163411 100644
--- a/ext/standard/basic_functions.c
+++ b/ext/standard/basic_functions.c
@@ -885,6 +885,7 @@ PHP_RSHUTDOWN_FUNCTION(basic)
 	BLS_FETCH();
 
 	STR_FREE(BG(strtok_string));
+	BG(strtok_string) = NULL;
 #ifdef HAVE_PUTENV
 	zend_hash_destroy(&BG(putenv_ht));
 #endif