diff --git a/src/js/cosmetic-filtering.js b/src/js/cosmetic-filtering.js
index f12ff0506..14c033fe3 100644
--- a/src/js/cosmetic-filtering.js
+++ b/src/js/cosmetic-filtering.js
@@ -408,9 +408,10 @@ SelectorCacheEntry.prototype.add = function(selectors, type) {
 // https://github.com/gorhill/uBlock/issues/420
 SelectorCacheEntry.prototype.remove = function(type) {
     this.lastAccessTime = Date.now();
-    if ( type === 'cosmetic' ) {
+    if ( type === undefined || type === 'cosmetic' ) {
         this.cosmetic = {};
-    } else {
+    }
+    if ( type === undefined || type === 'net' ) {
         this.net = {};
         this.netCount = 0;
     }
diff --git a/src/js/messaging.js b/src/js/messaging.js
index e3cbeb4cd..22894d903 100644
--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@@ -752,6 +752,9 @@ var onMessage = function(request, sender, callback) {
             break;
 
         case 'setSessionFirewallRules':
+            // https://github.com/gorhill/uBlock/issues/772
+            µb.cosmeticFilteringEngine.removeFromSelectorCache('*');
+
             µb.sessionFirewall.fromString(request.rules);
             response = getFirewallRules();
             break;