diff --git a/apply.c b/apply.c
index 7ffadc3b17..e82a7c30f0 100644
--- a/apply.c
+++ b/apply.c
@@ -3589,7 +3589,7 @@ static int try_threeway(struct apply_state *state,
 
 	/* Preimage the patch was prepared for */
 	if (patch->is_new)
-		write_object_file("", 0, blob_type, &pre_oid);
+		write_object_file("", 0, OBJ_BLOB, &pre_oid);
 	else if (get_oid(patch->old_oid_prefix, &pre_oid) ||
 		 read_blob_object(&buf, &pre_oid, patch->old_mode))
 		return error(_("repository lacks the necessary blob to perform 3-way merge."));
@@ -3605,7 +3605,7 @@ static int try_threeway(struct apply_state *state,
 		return -1;
 	}
 	/* post_oid is theirs */
-	write_object_file(tmp_image.buf, tmp_image.len, blob_type, &post_oid);
+	write_object_file(tmp_image.buf, tmp_image.len, OBJ_BLOB, &post_oid);
 	clear_image(&tmp_image);
 
 	/* our_oid is ours */
@@ -3618,7 +3618,7 @@ static int try_threeway(struct apply_state *state,
 			return error(_("cannot read the current contents of '%s'"),
 				     patch->old_name);
 	}
-	write_object_file(tmp_image.buf, tmp_image.len, blob_type, &our_oid);
+	write_object_file(tmp_image.buf, tmp_image.len, OBJ_BLOB, &our_oid);
 	clear_image(&tmp_image);
 
 	/* in-core three-way merge between post and our using pre as base */
@@ -4346,7 +4346,7 @@ static int add_index_file(struct apply_state *state,
 			}
 			fill_stat_cache_info(state->repo->index, ce, &st);
 		}
-		if (write_object_file(buf, size, blob_type, &ce->oid) < 0) {
+		if (write_object_file(buf, size, OBJ_BLOB, &ce->oid) < 0) {
 			discard_cache_entry(ce);
 			return error(_("unable to create backing store "
 				       "for newly created file %s"), path);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index cc804ba8e1..24cc235939 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -298,7 +298,7 @@ static int checkout_merged(int pos, const struct checkout *state,
 	 * (it also writes the merge result to the object database even
 	 * when it may contain conflicts).
 	 */
-	if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
+	if (write_object_file(result_buf.ptr, result_buf.size, OBJ_BLOB, &oid))
 		die(_("Unable to add merge result for '%s'"), path);
 	free(result_buf.ptr);
 	ce = make_transient_cache_entry(mode, &oid, path, 2, ce_mem_pool);
diff --git a/builtin/mktag.c b/builtin/mktag.c
index 3b2dbbb37e..96a3686af5 100644
--- a/builtin/mktag.c
+++ b/builtin/mktag.c
@@ -100,7 +100,7 @@ int cmd_mktag(int argc, const char **argv, const char *prefix)
 	if (verify_object_in_tag(&tagged_oid, &tagged_type))
 		die(_("tag on stdin did not refer to a valid object"));
 
-	if (write_object_file(buf.buf, buf.len, tag_type, &result) < 0)
+	if (write_object_file(buf.buf, buf.len, OBJ_TAG, &result) < 0)
 		die(_("unable to write tag file"));
 
 	strbuf_release(&buf);
diff --git a/builtin/mktree.c b/builtin/mktree.c
index ae78ca1c02..a1213aaa96 100644
--- a/builtin/mktree.c
+++ b/builtin/mktree.c
@@ -58,7 +58,7 @@ static void write_tree(struct object_id *oid)
 		strbuf_add(&buf, ent->oid.hash, the_hash_algo->rawsz);
 	}
 
-	write_object_file(buf.buf, buf.len, tree_type, oid);
+	write_object_file(buf.buf, buf.len, OBJ_TREE, oid);
 	strbuf_release(&buf);
 }
 
diff --git a/builtin/notes.c b/builtin/notes.c
index 05d60483e8..4cc84dfa76 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -199,7 +199,7 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 
 static void write_note_data(struct note_data *d, struct object_id *oid)
 {
-	if (write_object_file(d->buf.buf, d->buf.len, blob_type, oid)) {
+	if (write_object_file(d->buf.buf, d->buf.len, OBJ_BLOB, oid)) {
 		int status = die_message(_("unable to write note object"));
 
 		if (d->edit_path)
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 9f4a0b816c..231d576927 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -762,7 +762,7 @@ static void prepare_push_cert_sha1(struct child_process *proc)
 		int bogs /* beginning_of_gpg_sig */;
 
 		already_done = 1;
-		if (write_object_file(push_cert.buf, push_cert.len, "blob",
+		if (write_object_file(push_cert.buf, push_cert.len, OBJ_BLOB,
 				      &push_cert_oid))
 			oidclr(&push_cert_oid);
 
diff --git a/builtin/replace.c b/builtin/replace.c
index 6ff1734d58..995ca68330 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -474,7 +474,7 @@ static int create_graft(int argc, const char **argv, int force, int gentle)
 		return -1;
 	}
 
-	if (write_object_file(buf.buf, buf.len, commit_type, &new_oid)) {
+	if (write_object_file(buf.buf, buf.len, OBJ_COMMIT, &new_oid)) {
 		strbuf_release(&buf);
 		return error(_("could not write replacement commit for: '%s'"),
 			     old_ref);
diff --git a/builtin/tag.c b/builtin/tag.c
index 134b3f1edf..31e6b155c0 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -238,7 +238,7 @@ static int build_tag_object(struct strbuf *buf, int sign, struct object_id *resu
 {
 	if (sign && do_sign(buf) < 0)
 		return error(_("unable to sign the tag"));
-	if (write_object_file(buf->buf, buf->len, tag_type, result) < 0)
+	if (write_object_file(buf->buf, buf->len, OBJ_TAG, result) < 0)
 		return error(_("unable to write tag file"));
 	return 0;
 }
diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index 4a9466295b..808041551f 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c
@@ -177,7 +177,7 @@ static void write_cached_object(struct object *obj, struct obj_buffer *obj_buf)
 	struct object_id oid;
 
 	if (write_object_file(obj_buf->buffer, obj_buf->size,
-			      type_name(obj->type), &oid) < 0)
+			      obj->type, &oid) < 0)
 		die("failed to write object %s", oid_to_hex(&obj->oid));
 	obj->flags |= FLAG_WRITTEN;
 }
@@ -243,7 +243,7 @@ static void write_object(unsigned nr, enum object_type type,
 			 void *buf, unsigned long size)
 {
 	if (!strict) {
-		if (write_object_file(buf, size, type_name(type),
+		if (write_object_file(buf, size, type,
 				      &obj_list[nr].oid) < 0)
 			die("failed to write object");
 		added_object(nr, type, buf, size);
@@ -251,7 +251,7 @@ static void write_object(unsigned nr, enum object_type type,
 		obj_list[nr].obj = NULL;
 	} else if (type == OBJ_BLOB) {
 		struct blob *blob;
-		if (write_object_file(buf, size, type_name(type),
+		if (write_object_file(buf, size, type,
 				      &obj_list[nr].oid) < 0)
 			die("failed to write object");
 		added_object(nr, type, buf, size);
diff --git a/cache-tree.c b/cache-tree.c
index 65ca993361..fdbbd191d2 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -440,7 +440,7 @@ static int update_one(struct cache_tree *it,
 	} else if (dryrun) {
 		hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 				 tree_type, &it->oid);
-	} else if (write_object_file_flags(buffer.buf, buffer.len, tree_type,
+	} else if (write_object_file_flags(buffer.buf, buffer.len, OBJ_TREE,
 					   &it->oid, flags & WRITE_TREE_SILENT
 					   ? HASH_SILENT : 0)) {
 		strbuf_release(&buffer);
diff --git a/commit.c b/commit.c
index a348f085b2..6cc0ba9c11 100644
--- a/commit.c
+++ b/commit.c
@@ -1567,7 +1567,7 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 		goto out;
 	}
 
-	result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
+	result = write_object_file(buffer.buf, buffer.len, OBJ_COMMIT, ret);
 out:
 	strbuf_release(&buffer);
 	return result;
diff --git a/match-trees.c b/match-trees.c
index df413989fa..49398e599f 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -235,7 +235,7 @@ static int splice_tree(const struct object_id *oid1, const char *prefix,
 		rewrite_with = oid2;
 	}
 	hashcpy(rewrite_here, rewrite_with->hash);
-	status = write_object_file(buf, sz, tree_type, result);
+	status = write_object_file(buf, sz, OBJ_TREE, result);
 	free(buf);
 	return status;
 }
diff --git a/merge-ort.c b/merge-ort.c
index c319797021..d4ba2955f1 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -1888,7 +1888,7 @@ static int handle_content_merge(struct merge_options *opt,
 
 		if (!ret &&
 		    write_object_file(result_buf.ptr, result_buf.size,
-				      blob_type, &result->oid))
+				      OBJ_BLOB, &result->oid))
 			ret = err(opt, _("Unable to add %s to database"),
 				  path);
 
@@ -3343,7 +3343,7 @@ static void write_tree(struct object_id *result_oid,
 	}
 
 	/* Write this object file out, and record in result_oid */
-	write_object_file(buf.buf, buf.len, tree_type, result_oid);
+	write_object_file(buf.buf, buf.len, OBJ_TREE, result_oid);
 	strbuf_release(&buf);
 }
 
diff --git a/merge-recursive.c b/merge-recursive.c
index d9457797db..e0cbbf2d02 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1373,7 +1373,7 @@ static int merge_mode_and_contents(struct merge_options *opt,
 
 			if (!ret &&
 			    write_object_file(result_buf.ptr, result_buf.size,
-					      blob_type, &result->blob.oid))
+					      OBJ_BLOB, &result->blob.oid))
 				ret = err(opt, _("Unable to add %s to database"),
 					  a->path);
 
diff --git a/notes-cache.c b/notes-cache.c
index 2473314d68..9dfd251a81 100644
--- a/notes-cache.c
+++ b/notes-cache.c
@@ -92,7 +92,7 @@ int notes_cache_put(struct notes_cache *c, struct object_id *key_oid,
 {
 	struct object_id value_oid;
 
-	if (write_object_file(data, size, "blob", &value_oid) < 0)
+	if (write_object_file(data, size, OBJ_BLOB, &value_oid) < 0)
 		return -1;
 	return add_note(&c->tree, key_oid, &value_oid, NULL);
 }
diff --git a/notes.c b/notes.c
index f87dac4068..7452e71cc8 100644
--- a/notes.c
+++ b/notes.c
@@ -675,7 +675,7 @@ static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
 		ret = tree_write_stack_finish_subtree(n);
 		if (ret)
 			return ret;
-		ret = write_object_file(n->buf.buf, n->buf.len, tree_type, &s);
+		ret = write_object_file(n->buf.buf, n->buf.len, OBJ_TREE, &s);
 		if (ret)
 			return ret;
 		strbuf_release(&n->buf);
@@ -836,7 +836,7 @@ int combine_notes_concatenate(struct object_id *cur_oid,
 	free(new_msg);
 
 	/* create a new blob object from buf */
-	ret = write_object_file(buf, buf_len, blob_type, cur_oid);
+	ret = write_object_file(buf, buf_len, OBJ_BLOB, cur_oid);
 	free(buf);
 	return ret;
 }
@@ -916,7 +916,7 @@ int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
 				 string_list_join_lines_helper, &buf))
 		goto out;
 
-	ret = write_object_file(buf.buf, buf.len, blob_type, cur_oid);
+	ret = write_object_file(buf.buf, buf.len, OBJ_BLOB, cur_oid);
 
 out:
 	strbuf_release(&buf);
@@ -1192,7 +1192,7 @@ int write_notes_tree(struct notes_tree *t, struct object_id *result)
 	ret = for_each_note(t, flags, write_each_note, &cb_data) ||
 	      write_each_non_note_until(NULL, &cb_data) ||
 	      tree_write_stack_finish_subtree(&root) ||
-	      write_object_file(root.buf.buf, root.buf.len, tree_type, result);
+	      write_object_file(root.buf.buf, root.buf.len, OBJ_TREE, result);
 	strbuf_release(&root.buf);
 	return ret;
 }
diff --git a/object-file.c b/object-file.c
index 3fcd46cf9e..59eb793e0a 100644
--- a/object-file.c
+++ b/object-file.c
@@ -2014,7 +2014,7 @@ static int freshen_packed_object(const struct object_id *oid)
 }
 
 int write_object_file_flags(const void *buf, unsigned long len,
-			    const char *type, struct object_id *oid,
+			    enum object_type type, struct object_id *oid,
 			    unsigned flags)
 {
 	char hdr[MAX_HEADER_LEN];
@@ -2023,7 +2023,7 @@ int write_object_file_flags(const void *buf, unsigned long len,
 	/* Normally if we have it in the pack then we do not bother writing
 	 * it out into .git/objects/??/?{38} file.
 	 */
-	write_object_file_prepare(the_hash_algo, buf, len, type, oid, hdr,
+	write_object_file_prepare(the_hash_algo, buf, len, type_name(type), oid, hdr,
 				  &hdrlen);
 	if (freshen_packed_object(oid) || freshen_loose_object(oid))
 		return 0;
@@ -2162,7 +2162,7 @@ static int index_mem(struct index_state *istate,
 	}
 
 	if (write_object)
-		ret = write_object_file(buf, size, type_name(type), oid);
+		ret = write_object_file(buf, size, type, oid);
 	else
 		hash_object_file(the_hash_algo, buf, size, type_name(type),
 				 oid);
@@ -2189,7 +2189,7 @@ static int index_stream_convert_blob(struct index_state *istate,
 				 get_conv_flags(flags));
 
 	if (write_object)
-		ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
+		ret = write_object_file(sbuf.buf, sbuf.len, OBJ_BLOB,
 					oid);
 	else
 		hash_object_file(the_hash_algo, sbuf.buf, sbuf.len,
@@ -2313,7 +2313,7 @@ int index_path(struct index_state *istate, struct object_id *oid,
 		if (!(flags & HASH_WRITE_OBJECT))
 			hash_object_file(the_hash_algo, sb.buf, sb.len,
 					 blob_type, oid);
-		else if (write_object_file(sb.buf, sb.len, blob_type, oid))
+		else if (write_object_file(sb.buf, sb.len, OBJ_BLOB, oid))
 			rc = error(_("%s: failed to insert into database"), path);
 		strbuf_release(&sb);
 		break;
diff --git a/object-store.h b/object-store.h
index 8b4413d0ce..eab1e2a967 100644
--- a/object-store.h
+++ b/object-store.h
@@ -250,10 +250,10 @@ void hash_object_file(const struct git_hash_algo *algo, const void *buf,
 		      struct object_id *oid);
 
 int write_object_file_flags(const void *buf, unsigned long len,
-			    const char *type, struct object_id *oid,
+			    enum object_type type, struct object_id *oid,
 			    unsigned flags);
 static inline int write_object_file(const void *buf, unsigned long len,
-				    const char *type, struct object_id *oid)
+				    enum object_type type, struct object_id *oid)
 {
 	return write_object_file_flags(buf, len, type, oid, 0);
 }
diff --git a/read-cache.c b/read-cache.c
index cbe73f14e5..b8ae30a0e7 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -735,7 +735,7 @@ static struct cache_entry *create_alias_ce(struct index_state *istate,
 void set_object_name_for_intent_to_add_entry(struct cache_entry *ce)
 {
 	struct object_id oid;
-	if (write_object_file("", 0, blob_type, &oid))
+	if (write_object_file("", 0, OBJ_BLOB, &oid))
 		die(_("cannot create an empty blob in the object database"));
 	oidcpy(&ce->oid, &oid);
 }