diff --git a/blob.c b/blob.c
index b9c7180b7c..36f9abda19 100644
--- a/blob.c
+++ b/blob.c
@@ -9,8 +9,7 @@ struct blob *lookup_blob(struct repository *r, const struct object_id *oid)
 {
 	struct object *obj = lookup_object(r, oid);
 	if (!obj)
-		return create_object(r, oid->hash,
-				     alloc_blob_node(r));
+		return create_object(r, oid, alloc_blob_node(r));
 	return object_as_type(r, obj, OBJ_BLOB, 0);
 }
 
diff --git a/commit-graph.c b/commit-graph.c
index 7c5e54875f..5a62131d68 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -1214,7 +1214,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
 		hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
 
 		graph_commit = lookup_commit(r, &cur_oid);
-		odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
+		odb_commit = (struct commit *)create_object(r, &cur_oid, alloc_commit_node(r));
 		if (parse_commit_internal(odb_commit, 0, 0)) {
 			graph_report(_("failed to parse commit %s from object database for commit-graph"),
 				     oid_to_hex(&cur_oid));
diff --git a/commit.c b/commit.c
index f47c75afae..b71ac195d4 100644
--- a/commit.c
+++ b/commit.c
@@ -59,8 +59,7 @@ struct commit *lookup_commit(struct repository *r, const struct object_id *oid)
 {
 	struct object *obj = lookup_object(r, oid);
 	if (!obj)
-		return create_object(r, oid->hash,
-				     alloc_commit_node(r));
+		return create_object(r, oid, alloc_commit_node(r));
 	return object_as_type(r, obj, OBJ_COMMIT, 0);
 }
 
diff --git a/object.c b/object.c
index dbfdbe504d..317647da3e 100644
--- a/object.c
+++ b/object.c
@@ -141,13 +141,13 @@ static void grow_object_hash(struct repository *r)
 	r->parsed_objects->obj_hash_size = new_hash_size;
 }
 
-void *create_object(struct repository *r, const unsigned char *sha1, void *o)
+void *create_object(struct repository *r, const struct object_id *oid, void *o)
 {
 	struct object *obj = o;
 
 	obj->parsed = 0;
 	obj->flags = 0;
-	hashcpy(obj->oid.hash, sha1);
+	oidcpy(&obj->oid, oid);
 
 	if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
 		grow_object_hash(r);
@@ -182,7 +182,7 @@ struct object *lookup_unknown_object(const struct object_id *oid)
 {
 	struct object *obj = lookup_object(the_repository, oid);
 	if (!obj)
-		obj = create_object(the_repository, oid->hash,
+		obj = create_object(the_repository, oid,
 				    alloc_object_node(the_repository));
 	return obj;
 }
diff --git a/object.h b/object.h
index 47301186a4..0120892bbd 100644
--- a/object.h
+++ b/object.h
@@ -118,7 +118,7 @@ struct object *get_indexed_object(unsigned int);
  */
 struct object *lookup_object(struct repository *r, const struct object_id *oid);
 
-void *create_object(struct repository *r, const unsigned char *sha1, void *obj);
+void *create_object(struct repository *r, const struct object_id *oid, void *obj);
 
 void *object_as_type(struct repository *r, struct object *obj, enum object_type type, int quiet);
 
diff --git a/tag.c b/tag.c
index 3ae00ba1ab..5db870edb9 100644
--- a/tag.c
+++ b/tag.c
@@ -102,8 +102,7 @@ struct tag *lookup_tag(struct repository *r, const struct object_id *oid)
 {
 	struct object *obj = lookup_object(r, oid);
 	if (!obj)
-		return create_object(r, oid->hash,
-				     alloc_tag_node(r));
+		return create_object(r, oid, alloc_tag_node(r));
 	return object_as_type(r, obj, OBJ_TAG, 0);
 }
 
diff --git a/tree.c b/tree.c
index 0ebb8c5b02..4720945e6a 100644
--- a/tree.c
+++ b/tree.c
@@ -199,8 +199,7 @@ struct tree *lookup_tree(struct repository *r, const struct object_id *oid)
 {
 	struct object *obj = lookup_object(r, oid);
 	if (!obj)
-		return create_object(r, oid->hash,
-				     alloc_tree_node(r));
+		return create_object(r, oid, alloc_tree_node(r));
 	return object_as_type(r, obj, OBJ_TREE, 0);
 }