diff --git a/read-cache.c b/read-cache.c
index fda78bc353afcfd4d01864f2a13158d9c9c55173..5cddbc325ff3f85c693f600836a08fac755846bb 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1256,7 +1256,7 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
 	if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
 		return error("bad signature");
 	hdr_version = ntohl(hdr->hdr_version);
-	if (hdr_version < 2 || 4 < hdr_version)
+	if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version)
 		return error("bad index version %d", hdr_version);
 	git_SHA1_Init(&c);
 	git_SHA1_Update(&c, hdr, size - 20);