diff --git a/relay/http_client.py b/relay/http_client.py
index 79ac8b9..57c0562 100644
--- a/relay/http_client.py
+++ b/relay/http_client.py
@@ -3,7 +3,7 @@ import traceback
 
 from aiohttp import ClientSession, ClientTimeout, TCPConnector
 from aiohttp.client_exceptions import ClientConnectorError, ServerTimeoutError
-from aputils import Nodeinfo, WellKnownNodeinfo
+from aputils import Nodeinfo, WellKnownNodeinfo, AlgorithmType
 from datetime import datetime
 from cachetools import LRUCache
 from json.decoder import JSONDecodeError
@@ -141,10 +141,10 @@ class HttpClient:
 
 		# Using the old algo by default is probably a better idea right now
 		if (instance and instance.get('software') in {'mastodon'}) or (software and software in {'mastodon'}):
-			algorithm = 'hs2019'
+			algorithm = AlgorithmType.HS2019
 
 		else:
-			algorithm = 'original'
+			algorithm = AlgorithmType.ORIGINAL
 
 		headers = {'Content-Type': 'application/activity+json'}
 		headers.update(self.database.signer.sign_headers(