diff --git a/lib/filter-component.js b/lib/filter-component.js
index 8534d420d..35d21f380 100644
--- a/lib/filter-component.js
+++ b/lib/filter-component.js
@@ -40,13 +40,13 @@ function FilterComponent(filter_json) {
     this.types = filter_json.types || null;
     this.not_types = filter_json.not_types || [];
 
-    self.rooms = filter_json.rooms || null;
-    self.not_rooms = filter_json.not_rooms || [];
+    this.rooms = filter_json.rooms || null;
+    this.not_rooms = filter_json.not_rooms || [];
 
-    self.senders = filter_json.senders || null;
-    self.not_senders = filter_json.not_senders || [];
+    this.senders = filter_json.senders || null;
+    this.not_senders = filter_json.not_senders || [];
 
-    self.contains_url = filter_json.contains_url || null;
+    this.contains_url = filter_json.contains_url || null;
 };
 
 /**
diff --git a/lib/filter.js b/lib/filter.js
index ff81d2fcd..2a4f0fb4f 100644
--- a/lib/filter.js
+++ b/lib/filter.js
@@ -113,7 +113,9 @@ Filter.prototype.setDefinition = function(definition) {
     }
 
     this._room_filter = new FilterComponent(room_filter_fields);
-    this._room_timeline_filter = new FilterComponent(room_filter_json.timeline || {});
+    this._room_timeline_filter = new FilterComponent(
+        room_filter_json ? (room_filter_json.timeline || {}) : {}
+    );
 
     // don't bother porting this from synapse yet:
     // this._room_state_filter = new FilterComponent(room_filter_json.state || {});