diff --git a/synapse/rest/client/v2_alpha/thirdparty.py b/synapse/rest/client/v2_alpha/thirdparty.py
index 31f94bc6e..6fceb23e2 100644
--- a/synapse/rest/client/v2_alpha/thirdparty.py
+++ b/synapse/rest/client/v2_alpha/thirdparty.py
@@ -36,7 +36,7 @@ class ThirdPartyProtocolsServlet(RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request):
-        yield self.auth.get_user_by_req(request)
+        yield self.auth.get_user_by_req(request, allow_guest=True)
 
         protocols = yield self.appservice_handler.get_3pe_protocols()
         defer.returnValue((200, protocols))
@@ -54,7 +54,7 @@ class ThirdPartyProtocolServlet(RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, protocol):
-        yield self.auth.get_user_by_req(request)
+        yield self.auth.get_user_by_req(request, allow_guest=True)
 
         protocols = yield self.appservice_handler.get_3pe_protocols(
             only_protocol=protocol,
@@ -77,7 +77,7 @@ class ThirdPartyUserServlet(RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, protocol):
-        yield self.auth.get_user_by_req(request)
+        yield self.auth.get_user_by_req(request, allow_guest=True)
 
         fields = request.args
         fields.pop("access_token", None)
@@ -101,7 +101,7 @@ class ThirdPartyLocationServlet(RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, protocol):
-        yield self.auth.get_user_by_req(request)
+        yield self.auth.get_user_by_req(request, allow_guest=True)
 
         fields = request.args
         fields.pop("access_token", None)