diff --git a/refs.c b/refs.c
index beb49fb297..143936a9c3 100644
--- a/refs.c
+++ b/refs.c
@@ -1705,7 +1705,7 @@ int create_symref(const char *ref_target, const char *refs_heads_master,
 int ref_update_reject_duplicates(struct string_list *refnames,
 				 struct strbuf *err)
 {
-	int i, n = refnames->nr;
+	size_t i, n = refnames->nr;
 
 	assert(err);