diff --git a/merge-ort.c b/merge-ort.c
index 27a58a735d..289a61822f 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -3822,15 +3822,16 @@ static int tree_entry_order(const void *a_, const void *b_)
 				 b->string, strlen(b->string), bmi->result.mode);
 }
 
-static int write_tree(struct object_id *result_oid,
+static int write_tree(struct repository *repo,
+		      struct object_id *result_oid,
 		      struct string_list *versions,
-		      unsigned int offset,
-		      size_t hash_size)
+		      unsigned int offset)
 {
 	size_t maxlen = 0, extra;
 	unsigned int nr;
 	struct strbuf buf = STRBUF_INIT;
 	int i, ret = 0;
+	size_t hash_size = repo->hash_algo->rawsz;
 
 	assert(offset <= versions->nr);
 	nr = versions->nr - offset;
@@ -3856,7 +3857,7 @@ static int write_tree(struct object_id *result_oid,
 	}
 
 	/* Write this object file out, and record in result_oid */
-	if (odb_write_object(the_repository->objects, buf.buf,
+	if (odb_write_object(repo->objects, buf.buf,
 			     buf.len, OBJ_TREE, result_oid))
 		ret = -1;
 	strbuf_release(&buf);
@@ -4026,8 +4027,8 @@ static int write_completed_directory(struct merge_options *opt,
 		dir_info->is_null = 0;
 		dir_info->result.mode = S_IFDIR;
 		if (record_tree &&
-		    write_tree(&dir_info->result.oid, &info->versions, offset,
-			       opt->repo->hash_algo->rawsz) < 0)
+		    write_tree(opt->repo, &dir_info->result.oid, &info->versions,
+			       offset) < 0)
 			ret = -1;
 	}
 
@@ -4573,8 +4574,7 @@ static int process_entries(struct merge_options *opt,
 		BUG("dir_metadata accounting completely off; shouldn't happen");
 	}
 	if (record_tree &&
-	    write_tree(result_oid, &dir_metadata.versions, 0,
-		       opt->repo->hash_algo->rawsz) < 0)
+	    write_tree(opt->repo, result_oid, &dir_metadata.versions, 0) < 0)
 		ret = -1;
 cleanup:
 	string_list_clear(&plist, 0);