diff --git a/src/js/contentscript-end.js b/src/js/contentscript-end.js
index 9aa3644d3..ae7867bf2 100644
--- a/src/js/contentscript-end.js
+++ b/src/js/contentscript-end.js
@@ -20,6 +20,7 @@
 */
 
 /* global vAPI */
+
 'use strict';
 
 /******************************************************************************/
@@ -42,7 +43,7 @@ var messager = vAPI.messaging.channel('contentscript-end.js');
 
 (function() {
     var queriedSelectors = {};
-    var injectedSelectors = {};
+    var injectedSelectors = vAPI.injectedCosmeticFilters || {};
     var classSelectors = null;
     var idSelectors = null;
     var highGenerics = null;
@@ -50,57 +51,18 @@ var messager = vAPI.messaging.channel('contentscript-end.js');
     var nullArray = { push: function(){} };
 
     var domLoaded = function() {
-        var style = document.getElementById('ublock-preload-1ae7a5f130fc79b4fdb8a4272d9426b5');
-        if ( style ) {
-            // https://github.com/gorhill/uBlock/issues/14
-            // Treat any existing domain-specific exception selectors as if
-            // they had been injected already.
-            var selectors, i;
-            var exceptions = style.getAttribute('data-ublock-exceptions');
-            if ( exceptions ) {
-                selectors = JSON.parse(exceptions);
-                i = selectors.length;
-                while ( i-- ) {
-                    injectedSelectors[selectors[i]] = true;
-                }
-            }
-            // Avoid re-injecting already injected CSS rules.
-            selectors = selectorsFromStyles(style);
-            i = selectors.length;
-            while ( i-- ) {
-                injectedSelectors[selectors[i]] = true;
-            }
-            // https://github.com/gorhill/uBlock/issues/158
-            // Ensure injected styles are enforced
-            hideElements(selectors.join(','));
+        // https://github.com/gorhill/uBlock/issues/158
+        // Ensure injected styles are enforced
+        // rhill 2014-11-16: not sure this is needed anymore. Test case in
+        //  above issue was fine without the line below..
+        if ( vAPI.injectedCosmeticFilters ) {
+            hideElements(Object.keys(vAPI.injectedCosmeticFilters).join(','));
         }
         idsFromNodeList(document.querySelectorAll('[id]'));
         classesFromNodeList(document.querySelectorAll('[class]'));
         retrieveGenericSelectors();
     };
 
-    var selectorsFromStyles = function(styleRef) {
-        var selectors = [];
-        var styles = typeof styleRef === 'string' ?
-            document.querySelectorAll(styleRef):
-            [styleRef];
-        var i = styles.length;
-        var style, subset, lastSelector, pos;
-        while ( i-- ) {
-            style = styles[i];
-            subset = style.textContent.split(',\n');
-            lastSelector = subset.pop();
-            if ( lastSelector ) {
-                pos = lastSelector.indexOf('\n');
-                if ( pos !== -1 ) {
-                    subset.push(lastSelector.slice(0, pos));
-                }
-            }
-            selectors = selectors.concat(subset);
-        }
-        return selectors;
-    };
-
     var retrieveGenericSelectors = function() {
         var selectors = classSelectors !== null ? Object.keys(classSelectors) : [];
         if ( idSelectors !== null ) {
diff --git a/src/js/contentscript-start.js b/src/js/contentscript-start.js
index 3fbf3d8ab..533706df2 100644
--- a/src/js/contentscript-start.js
+++ b/src/js/contentscript-start.js
@@ -21,6 +21,7 @@
 
 /* jshint multistr: true */
 /* global vAPI */
+
 'use strict';
 
 /******************************************************************************/
@@ -54,6 +55,7 @@ var cosmeticFilters = function(details) {
     if ( style !== null ) {
         return;
     }
+    var injectedCosmeticFilters = {};
     style = document.createElement('style');
     style.setAttribute('id', 'ublock-preload-1ae7a5f130fc79b4fdb8a4272d9426b5');
     var donthide = details.cosmeticDonthide;
@@ -61,20 +63,22 @@ var cosmeticFilters = function(details) {
     if ( donthide.length !== 0 ) {
         donthide = donthide.length !== 1 ? donthide.join(',\n') : donthide[0];
         donthide = donthide.split(',\n');
-        style.setAttribute('data-ublock-exceptions', JSON.stringify(donthide));
+        var i = donthide.length;
+        while ( i-- ) {
+            injectedCosmeticFilters[donthide[i]] = true;
+        }
         // https://github.com/gorhill/uBlock/issues/143
         if ( hide.length !== 0 ) {
-            // I chose to use Array.indexOf() instead of converting the array to
-            // a map, then deleting whitelisted selectors, and then converting
-            // back the map into an array, because there are typically very few
-            // exception filters, if any.
             hide = hide.length !== 1 ? hide.join(',\n') : hide[0];
             hide = hide.split(',\n');
-            var i = donthide.length, j;
+            i = hide.length;
+            var selector;
             while ( i-- ) {
-                j = hide.indexOf(donthide[i]);
-                if ( j !== -1 ) {
-                    hide.splice(j, 1);
+                selector = hide[i];
+                if ( injectedCosmeticFilters[selector] ) {
+                    hide.splice(i, 1);
+                } else {
+                    injectedCosmeticFilters[selector] = true;
                 }
             }
         }
@@ -90,6 +94,7 @@ var cosmeticFilters = function(details) {
     if ( parent ) {
         parent.appendChild(style);
     }
+    vAPI.injectedCosmeticFilters = injectedCosmeticFilters;
 };
 
 var netFilters = function(details) {