diff --git a/include/git2/types.h b/include/git2/types.h
index a4afd18c3..fdccd9646 100644
--- a/include/git2/types.h
+++ b/include/git2/types.h
@@ -76,9 +76,7 @@ typedef enum {
 	GIT_OBJECT_COMMIT =    1, /**< A commit object. */
 	GIT_OBJECT_TREE =      2, /**< A tree (directory listing) object. */
 	GIT_OBJECT_BLOB =      3, /**< A file revision object. */
-	GIT_OBJECT_TAG =       4, /**< An annotated tag object. */
-	GIT_OBJECT_OFS_DELTA = 6, /**< A delta, base is given by an offset. */
-	GIT_OBJECT_REF_DELTA = 7  /**< A delta, base is given by object id. */
+	GIT_OBJECT_TAG =       4  /**< An annotated tag object. */
 } git_object_t;
 
 /**
diff --git a/src/libgit2/indexer.c b/src/libgit2/indexer.c
index f1c85cb88..cdd2b2431 100644
--- a/src/libgit2/indexer.c
+++ b/src/libgit2/indexer.c
@@ -319,9 +319,9 @@ static int advance_delta_offset(git_indexer *idx, git_object_t type)
 {
 	git_mwindow *w = NULL;
 
-	GIT_ASSERT_ARG(type == GIT_OBJECT_REF_DELTA || type == GIT_OBJECT_OFS_DELTA);
+	GIT_ASSERT_ARG(type == GIT_PACKFILE_REF_DELTA || type == GIT_PACKFILE_OFS_DELTA);
 
-	if (type == GIT_OBJECT_REF_DELTA) {
+	if (type == GIT_PACKFILE_REF_DELTA) {
 		idx->off += git_oid_size(idx->oid_type);
 	} else {
 		off64_t base_off;
@@ -813,7 +813,7 @@ static int read_stream_object(git_indexer *idx, git_indexer_progress *stats)
 		git_hash_init(&idx->hash_ctx);
 		git_str_clear(&idx->entry_data);
 
-		if (type == GIT_OBJECT_REF_DELTA || type == GIT_OBJECT_OFS_DELTA) {
+		if (type == GIT_PACKFILE_REF_DELTA || type == GIT_PACKFILE_OFS_DELTA) {
 			error = advance_delta_offset(idx, type);
 			if (error == GIT_EBUFS) {
 				idx->off = entry_start;
@@ -1094,7 +1094,7 @@ static int fix_thin_pack(git_indexer *idx, git_indexer_progress *stats)
 		if (error < 0)
 			return error;
 
-		if (type == GIT_OBJECT_REF_DELTA) {
+		if (type == GIT_PACKFILE_REF_DELTA) {
 			found_ref_delta = 1;
 			break;
 		}
diff --git a/src/libgit2/pack-objects.c b/src/libgit2/pack-objects.c
index ced98e8c8..efdd68aea 100644
--- a/src/libgit2/pack-objects.c
+++ b/src/libgit2/pack-objects.c
@@ -338,7 +338,7 @@ static int write_object(
 				goto done;
 
 		data_len = po->delta_size;
-		type = GIT_OBJECT_REF_DELTA;
+		type = GIT_PACKFILE_REF_DELTA;
 	} else {
 		if ((error = git_odb_read(&obj, pb->odb, &po->id)) < 0)
 			goto done;
@@ -354,7 +354,7 @@ static int write_object(
 	    (error = git_hash_update(&pb->ctx, hdr, hdr_len)) < 0)
 		goto done;
 
-	if (type == GIT_OBJECT_REF_DELTA) {
+	if (type == GIT_PACKFILE_REF_DELTA) {
 		if ((error = write_cb(po->delta->id.id, oid_size, cb_data)) < 0 ||
 		    (error = git_hash_update(&pb->ctx, po->delta->id.id, oid_size)) < 0)
 			goto done;
diff --git a/src/libgit2/pack.c b/src/libgit2/pack.c
index cf63b204e..a70975a75 100644
--- a/src/libgit2/pack.c
+++ b/src/libgit2/pack.c
@@ -390,7 +390,7 @@ int git_packfile__object_header(size_t *out, unsigned char *hdr, size_t size, gi
 	unsigned char *hdr_base;
 	unsigned char c;
 
-	GIT_ASSERT_ARG(type >= GIT_OBJECT_COMMIT && type <= GIT_OBJECT_REF_DELTA);
+	GIT_ASSERT_ARG(type >= GIT_OBJECT_COMMIT && type <= GIT_PACKFILE_REF_DELTA);
 
 	/* TODO: add support for chunked objects; see git.git 6c0d19b1 */
 
@@ -532,7 +532,7 @@ int git_packfile_resolve_header(
 	if (error < 0)
 		return error;
 
-	if (type == GIT_OBJECT_OFS_DELTA || type == GIT_OBJECT_REF_DELTA) {
+	if (type == GIT_PACKFILE_OFS_DELTA || type == GIT_PACKFILE_REF_DELTA) {
 		size_t base_size;
 		git_packfile_stream stream;
 
@@ -553,12 +553,12 @@ int git_packfile_resolve_header(
 		base_offset = 0;
 	}
 
-	while (type == GIT_OBJECT_OFS_DELTA || type == GIT_OBJECT_REF_DELTA) {
+	while (type == GIT_PACKFILE_OFS_DELTA || type == GIT_PACKFILE_REF_DELTA) {
 		curpos = base_offset;
 		error = git_packfile_unpack_header(&size, &type, p, &w_curs, &curpos);
 		if (error < 0)
 			return error;
-		if (type != GIT_OBJECT_OFS_DELTA && type != GIT_OBJECT_REF_DELTA)
+		if (type != GIT_PACKFILE_OFS_DELTA && type != GIT_PACKFILE_REF_DELTA)
 			break;
 
 		error = get_delta_base(&base_offset, p, &w_curs, &curpos, type, base_offset);
@@ -635,7 +635,7 @@ static int pack_dependency_chain(git_dependency_chain *chain_out,
 		elem->type = type;
 		elem->base_key = obj_offset;
 
-		if (type != GIT_OBJECT_OFS_DELTA && type != GIT_OBJECT_REF_DELTA)
+		if (type != GIT_PACKFILE_OFS_DELTA && type != GIT_PACKFILE_REF_DELTA)
 			break;
 
 		error = get_delta_base(&base_offset, p, &w_curs, &curpos, type, obj_offset);
@@ -675,7 +675,7 @@ int git_packfile_unpack(
 	git_pack_cache_entry *cached = NULL;
 	struct pack_chain_elem small_stack[SMALL_STACK_SIZE];
 	size_t stack_size = 0, elem_pos, alloclen;
-	git_object_t base_type;
+	int base_type;
 
 	error = git_mutex_lock(&p->lock);
 	if (error < 0) {
@@ -735,8 +735,8 @@ int git_packfile_unpack(
 		if (error < 0)
 			goto cleanup;
 		break;
-	case GIT_OBJECT_OFS_DELTA:
-	case GIT_OBJECT_REF_DELTA:
+	case GIT_PACKFILE_OFS_DELTA:
+	case GIT_PACKFILE_REF_DELTA:
 		error = packfile_error("dependency chain ends in a delta");
 		goto cleanup;
 	default:
@@ -983,7 +983,7 @@ int get_delta_base(
 	 * than the hash size is stupid, as then a REF_DELTA would be
 	 * smaller to store.
 	 */
-	if (type == GIT_OBJECT_OFS_DELTA) {
+	if (type == GIT_PACKFILE_OFS_DELTA) {
 		unsigned used = 0;
 		unsigned char c = base_info[used++];
 		size_t unsigned_base_offset = c & 127;
@@ -1000,7 +1000,7 @@ int get_delta_base(
 			return packfile_error("out of bounds");
 		base_offset = delta_obj_offset - unsigned_base_offset;
 		*curpos += used;
-	} else if (type == GIT_OBJECT_REF_DELTA) {
+	} else if (type == GIT_PACKFILE_REF_DELTA) {
 		git_oid base_oid;
 		git_oid_from_raw(&base_oid, base_info, p->oid_type);
 
diff --git a/src/libgit2/pack.h b/src/libgit2/pack.h
index 4fd092149..e802d6074 100644
--- a/src/libgit2/pack.h
+++ b/src/libgit2/pack.h
@@ -33,6 +33,10 @@ typedef int git_pack_foreach_entry_offset_cb(
 #define PACK_SIGNATURE 0x5041434b	/* "PACK" */
 #define PACK_VERSION 2
 #define pack_version_ok(v) ((v) == htonl(2))
+
+#define GIT_PACKFILE_OFS_DELTA 6
+#define GIT_PACKFILE_REF_DELTA 7
+
 struct git_pack_header {
 	uint32_t hdr_signature;
 	uint32_t hdr_version;
diff --git a/tests/libgit2/object/raw/hash.c b/tests/libgit2/object/raw/hash.c
index 3bfaddaa2..914096f6a 100644
--- a/tests/libgit2/object/raw/hash.c
+++ b/tests/libgit2/object/raw/hash.c
@@ -87,16 +87,16 @@ void test_object_raw_hash__hash_junk_data(void)
 	junk_obj.data = some_data;
 	hash_object_fail(&id, &junk_obj);
 
-	junk_obj.type = 0; /* EXT1 */
+	junk_obj.type = 0; /* unused */
 	hash_object_fail(&id, &junk_obj);
 
-	junk_obj.type = 5; /* EXT2 */
+	junk_obj.type = 5; /* unused */
 	hash_object_fail(&id, &junk_obj);
 
-	junk_obj.type = GIT_OBJECT_OFS_DELTA;
+	junk_obj.type = 6; /* packfile offset delta */
 	hash_object_fail(&id, &junk_obj);
 
-	junk_obj.type = GIT_OBJECT_REF_DELTA;
+	junk_obj.type = 7; /* packfile ref delta */
 	hash_object_fail(&id, &junk_obj);
 
 	junk_obj.type = 42;
diff --git a/tests/libgit2/object/raw/type2string.c b/tests/libgit2/object/raw/type2string.c
index 6f0b47603..e3a0764e5 100644
--- a/tests/libgit2/object/raw/type2string.c
+++ b/tests/libgit2/object/raw/type2string.c
@@ -7,14 +7,14 @@
 void test_object_raw_type2string__convert_type_to_string(void)
 {
 	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_INVALID), "");
-	cl_assert_equal_s(git_object_type2string(0), ""); /* EXT1 */
+	cl_assert_equal_s(git_object_type2string(0), ""); /* unused */
 	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_COMMIT), "commit");
 	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_TREE), "tree");
 	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_BLOB), "blob");
 	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_TAG), "tag");
-	cl_assert_equal_s(git_object_type2string(5), ""); /* EXT2 */
-	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_OFS_DELTA), "OFS_DELTA");
-	cl_assert_equal_s(git_object_type2string(GIT_OBJECT_REF_DELTA), "REF_DELTA");
+	cl_assert_equal_s(git_object_type2string(5), ""); /* unused */
+	cl_assert_equal_s(git_object_type2string(6), ""); /* packfile offset delta */
+	cl_assert_equal_s(git_object_type2string(7), ""); /* packfile ref delta */
 
 	cl_assert_equal_s(git_object_type2string(-2), "");
 	cl_assert_equal_s(git_object_type2string(8), "");
@@ -29,8 +29,8 @@ void test_object_raw_type2string__convert_string_to_type(void)
 	cl_assert(git_object_string2type("tree") == GIT_OBJECT_TREE);
 	cl_assert(git_object_string2type("blob") == GIT_OBJECT_BLOB);
 	cl_assert(git_object_string2type("tag") == GIT_OBJECT_TAG);
-	cl_assert(git_object_string2type("OFS_DELTA") == GIT_OBJECT_OFS_DELTA);
-	cl_assert(git_object_string2type("REF_DELTA") == GIT_OBJECT_REF_DELTA);
+	cl_assert(git_object_string2type("OFS_DELTA") == GIT_OBJECT_INVALID);
+	cl_assert(git_object_string2type("REF_DELTA") == GIT_OBJECT_INVALID);
 
 	cl_assert(git_object_string2type("CoMmIt") == GIT_OBJECT_INVALID);
 	cl_assert(git_object_string2type("hohoho") == GIT_OBJECT_INVALID);
@@ -39,14 +39,14 @@ void test_object_raw_type2string__convert_string_to_type(void)
 void test_object_raw_type2string__check_type_is_valid(void)
 {
 	cl_assert(git_object_type_is_valid(GIT_OBJECT_INVALID) == 0);
-	cl_assert(git_object_type_is_valid(0) == 0); /* EXT1 */
+	cl_assert(git_object_type_is_valid(0) == 0); /* unused */
 	cl_assert(git_object_type_is_valid(GIT_OBJECT_COMMIT) == 1);
 	cl_assert(git_object_type_is_valid(GIT_OBJECT_TREE) == 1);
 	cl_assert(git_object_type_is_valid(GIT_OBJECT_BLOB) == 1);
 	cl_assert(git_object_type_is_valid(GIT_OBJECT_TAG) == 1);
-	cl_assert(git_object_type_is_valid(5) == 0); /* EXT2 */
-	cl_assert(git_object_type_is_valid(GIT_OBJECT_OFS_DELTA) == 0);
-	cl_assert(git_object_type_is_valid(GIT_OBJECT_REF_DELTA) == 0);
+	cl_assert(git_object_type_is_valid(5) == 0); /* unused */
+	cl_assert(git_object_type_is_valid(6) == 0); /* packfile offset delta */
+	cl_assert(git_object_type_is_valid(7) == 0); /* packfile ref delta */
 
 	cl_assert(git_object_type_is_valid(-2) == 0);
 	cl_assert(git_object_type_is_valid(8) == 0);
diff --git a/tests/libgit2/repo/hashfile.c b/tests/libgit2/repo/hashfile.c
index f053cb950..64b8dfa46 100644
--- a/tests/libgit2/repo/hashfile.c
+++ b/tests/libgit2/repo/hashfile.c
@@ -34,7 +34,7 @@ void test_repo_hashfile__simple(void)
 
 	/* hash with invalid type */
 	cl_git_fail(git_odb__hashfile(&a, full.ptr, GIT_OBJECT_ANY, GIT_OID_SHA1));
-	cl_git_fail(git_repository_hashfile(&b, _repo, full.ptr, GIT_OBJECT_OFS_DELTA, NULL));
+	cl_git_fail(git_repository_hashfile(&b, _repo, full.ptr, 6, NULL));
 
 	git_str_dispose(&full);
 }