diff --git a/convert.c b/convert.c
index a34ec6ecdc..eae36c8a59 100644
--- a/convert.c
+++ b/convert.c
@@ -1168,7 +1168,8 @@ static int ident_to_worktree(const char *src, size_t len,
 			     struct strbuf *buf, int ident)
 {
 	struct object_id oid;
-	char *to_free = NULL, *dollar, *spc;
+	char *to_free = NULL;
+	const char *dollar, *spc;
 	int cnt;
 
 	if (!ident)