diff --git a/src/js/cosmetic-filtering.js b/src/js/cosmetic-filtering.js
index 30591cc04..ebd827759 100644
--- a/src/js/cosmetic-filtering.js
+++ b/src/js/cosmetic-filtering.js
@@ -639,6 +639,10 @@ FilterContainer.prototype.reset = function() {
 
     this.selectorCache = {};
     this.selectorCacheCount = 0;
+    if ( this.selectorCacheTimer !== null ) {
+        clearTimeout(this.selectorCacheTimer);
+        this.selectorCacheTimer = null;
+    }
 
     // permanent
     // [class], [id]
diff --git a/src/js/start.js b/src/js/start.js
index 077f20d51..440ba106d 100644
--- a/src/js/start.js
+++ b/src/js/start.js
@@ -41,6 +41,7 @@ vAPI.app.onShutdown = function() {
     µb.staticFilteringReverseLookup.shutdown();
     µb.assetUpdater.shutdown();
     µb.staticNetFilteringEngine.reset();
+    µb.cosmeticFilteringEngine.reset();
     µb.sessionFirewall.reset();
     µb.permanentFirewall.reset();
     µb.permanentFirewall.reset();