diff --git a/pantalaimon/daemon.py b/pantalaimon/daemon.py
index 8ad2b93..0e1bd97 100755
--- a/pantalaimon/daemon.py
+++ b/pantalaimon/daemon.py
@@ -411,29 +411,34 @@ class ProxyDaemon:
 
         return access_token
 
+    def sanitize_subfilter(self, request_filter: Dict[Any, Any]):
+        types_filter = request_filter.get("types", None)
+
+        if types_filter:
+            if "m.room.encrypted" not in types_filter:
+                types_filter.append("m.room.encrypted")
+
+        not_types_filter = request_filter.get("not_types", None)
+
+        if not_types_filter:
+            try:
+                not_types_filter.remove("m.room.encrypted")
+            except ValueError:
+                pass
+
     def sanitize_filter(self, sync_filter):
         # type: (Dict[Any, Any]) -> Dict[Any, Any]
         """Make sure that a filter isn't filtering encrypted messages."""
         sync_filter = dict(sync_filter)
         room_filter = sync_filter.get("room", None)
 
+        self.sanitize_subfilter(sync_filter)
+
         if room_filter:
             timeline_filter = room_filter.get("timeline", None)
 
             if timeline_filter:
-                types_filter = timeline_filter.get("types", None)
-
-                if types_filter:
-                    if "m.room.encrypted" not in types_filter:
-                        types_filter.append("m.room.encrypted")
-
-                not_types_filter = timeline_filter.get("not_types", None)
-
-                if not_types_filter:
-                    try:
-                        not_types_filter.remove("m.room.encrypted")
-                    except ValueError:
-                        pass
+                self.sanitize_subfilter(timeline_filter)
 
         return sync_filter
 
@@ -763,8 +768,22 @@ class ProxyDaemon:
         if not client:
             return self._unknown_token
 
+        request_filter = request.query.get("filter", None)
+        query = CIMultiDict(request.query)
+
+        if request_filter:
+            try:
+                request_filter = json.loads(request_filter)
+            except (JSONDecodeError, TypeError):
+                pass
+
+            if isinstance(request_filter, dict):
+                request_filter = json.dumps(self.sanitize_filter(request_filter))
+
+            query["filter"] = request_filter
+
         try:
-            response = await self.forward_request(request)
+            response = await self.forward_request(request, params=query)
         except ClientConnectionError as e:
             return web.Response(status=500, text=str(e))