diff --git a/config.c b/config.c
index a677eb6c59..123ed29963 100644
--- a/config.c
+++ b/config.c
@@ -2083,6 +2083,7 @@ int git_config_set_multivar_in_file(const char *config_filename,
 	if (commit_lock_file(lock) < 0) {
 		error("could not commit config file %s", config_filename);
 		ret = CONFIG_NO_WRITE;
+		lock = NULL;
 		goto out_free;
 	}