diff --git a/builtin/stash.c b/builtin/stash.c
index fe64cde9ce..c9365bea13 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -362,7 +362,7 @@ static int is_path_a_directory(const char *path)
 }
 
 static void add_diff_to_buf(struct diff_queue_struct *q,
-			    struct diff_options *options,
+			    struct diff_options *options UNUSED,
 			    void *data)
 {
 	int i;