diff --git a/diffcore-rename.c b/diffcore-rename.c
index 57a74b6bb83e14af5f7336f397f79fbfcdc8b5f7..91fa2bea519a39ee65dcf018b7a72885b9eeec70 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -109,6 +109,8 @@ static int is_exact_match(struct diff_filespec *src,
 		return 0;
 	if (src->size != dst->size)
 		return 0;
+	if (src->sha1_valid && dst->sha1_valid)
+	    return !hashcmp(src->sha1, dst->sha1);
 	if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
 		return 0;
 	if (src->size == dst->size &&