diff --git a/relay.yaml.example b/relay.yaml.example
index 0f7f949..68f0016 100644
--- a/relay.yaml.example
+++ b/relay.yaml.example
@@ -21,4 +21,10 @@ ap:
   whitelist:
   - 'good-instance.example.com'
   - 'another.good-instance.example.com'
-  block_relays: false
+  # uncomment the lines below to prevent certain activitypub software from posting
+  # to the relay (all known relays by default). this uses the software name in nodeinfo
+  #blocked_software:
+  #- 'activityrelay'
+  #- 'aoderelay'
+  #- 'social.seattle.wa.us-relay'
+  #- 'unciarelay'
diff --git a/relay/__init__.py b/relay/__init__.py
index cad19ce..3785de6 100644
--- a/relay/__init__.py
+++ b/relay/__init__.py
@@ -23,7 +23,7 @@ def load_config():
             'port': int(yaml_file.get('port', 8080)),
             'note': yaml_file.get('note', 'Make a note about your instance here.'),
             'ap': {
-                'block_relays': yaml_file['ap'].get('block_relays', False),
+                'blocked_software': [v.lower() for v in yaml_file['ap'].get('blocked_software', [])],
                 'blocked_instances': yaml_file['ap'].get('blocked_instances', []),
                 'host': yaml_file['ap'].get('host', 'localhost'),
                 'whitelist': yaml_file['ap'].get('whitelist', []),
@@ -35,7 +35,6 @@ def load_config():
 
 CONFIG = load_config()
 
-
 from .http_signatures import http_signatures_middleware
 
 
diff --git a/relay/actor.py b/relay/actor.py
index d0e1f8b..4264cca 100644
--- a/relay/actor.py
+++ b/relay/actor.py
@@ -318,10 +318,10 @@ async def inbox(request):
     data = await request.json()
     instance = urlsplit(data['actor']).hostname
 
-    if AP_CONFIG['block_relays']:
+    if AP_CONFIG['blocked_software']:
         software = await fetch_nodeinfo(instance)
 
-        if software and 'relay' in software.lower():
+        if software and software.lower() in AP_CONFIG['blocked_software']:
             raise aiohttp.web.HTTPUnauthorized(body='relays have been blocked', content_type='text/plain')
 
     if 'actor' not in data or not request['validated']: