diff --git a/unpack-trees.c b/unpack-trees.c
index f9d12aafba..48d862d3b4 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1004,7 +1004,7 @@ int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
 
 	if (old && same(old, a)) {
 		int update = 0;
-		if (o->reset) {
+		if (o->reset && !ce_uptodate(old)) {
 			struct stat st;
 			if (lstat(old->name, &st) ||
 			    ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID))