diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index f176dd28c8..7bea1fba52 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1555,13 +1555,9 @@ static void read_v2_anomalous_offsets(struct packed_git *p,
 {
 	const uint32_t *idx1, *idx2;
 	uint32_t i;
-	const uint32_t hashwords = the_hash_algo->rawsz / sizeof(uint32_t);
 
 	/* The address of the 4-byte offset table */
-	idx1 = (((const uint32_t *)p->index_data)
-		+ 2 /* 8-byte header */
-		+ 256 /* fan out */
-		+ hashwords * p->num_objects /* object ID table */
+	idx1 = (((const uint32_t *)((const uint8_t *)p->index_data + p->crc_offset))
 		+ p->num_objects /* CRC32 table */
 		);
 
diff --git a/object-store.h b/object-store.h
index d1e490f203..f439d47af8 100644
--- a/object-store.h
+++ b/object-store.h
@@ -70,6 +70,7 @@ struct packed_git {
 	size_t index_size;
 	uint32_t num_objects;
 	uint32_t num_bad_objects;
+	uint32_t crc_offset;
 	unsigned char *bad_object_sha1;
 	int index_version;
 	time_t mtime;
diff --git a/packfile.c b/packfile.c
index f4e752996d..6ab5233613 100644
--- a/packfile.c
+++ b/packfile.c
@@ -178,6 +178,7 @@ int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 		     */
 		    (sizeof(off_t) <= 4))
 			return error("pack too large for current definition of off_t in %s", path);
+		p->crc_offset = 8 + 4 * 256 + nr * hashsz;
 	}
 
 	p->index_version = version;