diff --git a/src/components/structures/ScrollPanel.js b/src/components/structures/ScrollPanel.js
index 06c925e69e..ee4045c91e 100644
--- a/src/components/structures/ScrollPanel.js
+++ b/src/components/structures/ScrollPanel.js
@@ -178,10 +178,6 @@ module.exports = React.createClass({
         //
         // (We could use isMounted(), but facebook have deprecated that.)
         this.unmounted = true;
-        if (this._timelineSizeObserver) {
-            this._timelineSizeObserver.disconnect();
-            this._timelineSizeObserver = null;
-        }
     },
 
     onScroll: function(ev) {