diff --git a/lib/filter-component.js b/lib/filter-component.js
index 3930806f6..8534d420d 100644
--- a/lib/filter-component.js
+++ b/lib/filter-component.js
@@ -34,7 +34,7 @@ function _matches_wildcard(actual_value, filter_value) {
  *
  * This is all ported from synapse's Filter object.
  */
-FilterComponent = function(filter_json) {
+function FilterComponent(filter_json) {
     this.filter_json = filter_json;
 
     this.types = filter_json.types || null;
@@ -65,7 +65,7 @@ FilterComponent.prototype.check = function(event) {
         event.room_id,
         sender,
         event.type,
-        event.content ? event.content.url !== undefined : false,
+        event.content ? event.content.url !== undefined : false
     );
 };
 
@@ -73,38 +73,38 @@ FilterComponent.prototype.check = function(event) {
  * Checks whether the filter matches the given event fields.
  */
 FilterComponent.prototype.checkFields =
-    function(room_id, sender, event_type, contains_url) {
-        var literal_keys = {
-            "rooms": function(v) { return room_id === v; },
-            "senders": function(v) { return sender === v; },
-            "types": function(v) { return _matches_wildcard(event_type, v); },
-        };
+    function(room_id, sender, event_type, contains_url)
+{
+    var literal_keys = {
+        "rooms": function(v) { return room_id === v; },
+        "senders": function(v) { return sender === v; },
+        "types": function(v) { return _matches_wildcard(event_type, v); },
+    };
 
-        Object.keys(literal_keys).forEach(function(name) {
-            var match_func = literal_keys[name];
-            var not_name = "not_" + name;
-            var disallowed_values = this[not_name];
-            if (disallowed_values.map(match_func)) {
-                return false;
-            }
+    Object.keys(literal_keys).forEach(function(name) {
+        var match_func = literal_keys[name];
+        var not_name = "not_" + name;
+        var disallowed_values = this[not_name];
+        if (disallowed_values.map(match_func)) {
+            return false;
+        }
 
-            var allowed_values = this[name];
-            if (allowed_values) {
-                if (!allowed_values.map(match_func)) {
-                    return false;
-                }
-            }
-        });
-
-        contains_url_filter = this.filter_json.contains_url;
-        if (contains_url_filter !== undefined) {
-            if (contains_url_filter !== contains_url) {
+        var allowed_values = this[name];
+        if (allowed_values) {
+            if (!allowed_values.map(match_func)) {
                 return false;
             }
         }
+    });
 
-        return true;
+    contains_url_filter = this.filter_json.contains_url;
+    if (contains_url_filter !== undefined) {
+        if (contains_url_filter !== contains_url) {
+            return false;
+        }
     }
+
+    return true;
 };
 
 FilterComponent.prototype.filter = function(events) {