diff --git a/src/js/background.js b/src/js/background.js
index 11ec4c7e9..a9e99f636 100644
--- a/src/js/background.js
+++ b/src/js/background.js
@@ -120,6 +120,7 @@ var µBlock = (function() { // jshint ignore:line
         privacySettingsSupported: vAPI.browserSettings instanceof Object,
         cloudStorageSupported: vAPI.cloud instanceof Object,
         canFilterResponseBody: vAPI.net.canFilterResponseBody === true,
+        canInjectScriptletsNow: vAPI.webextFlavor.soup.has('chromium'),
 
         // https://github.com/chrisaljoudi/uBlock/issues/180
         // Whitelist directives need to be loaded once the PSL is available
diff --git a/src/js/contentscript.js b/src/js/contentscript.js
index eb97b75fa..916fb5b1e 100644
--- a/src/js/contentscript.js
+++ b/src/js/contentscript.js
@@ -349,12 +349,16 @@ vAPI.matchesProp = (function() {
 
 vAPI.injectScriptlet = function(doc, text) {
     if ( !doc ) { return; }
+    let script;
     try {
-        var script = doc.createElement('script');
+        script = doc.createElement('script');
         script.appendChild(doc.createTextNode(text));
         (doc.head || doc.documentElement).appendChild(script);
     } catch (ex) {
     }
+    if ( script && script.parentNode ) {
+        script.parentNode.removeChild(script);
+    }
 };
 
 /******************************************************************************/
diff --git a/src/js/messaging.js b/src/js/messaging.js
index f7199324c..f138d30a0 100644
--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@@ -520,6 +520,9 @@ var onMessage = function(request, sender, callback) {
         request.entity = µb.URI.entityFromDomain(request.domain);
         response.specificCosmeticFilters =
             µb.cosmeticFilteringEngine.retrieveDomainSelectors(request, response);
+        if ( µb.canInjectScriptletsNow === false ) {
+            response.scriptlets = µb.scriptletFilteringEngine.retrieve(request);
+        }
         if ( request.isRootFrame && µb.logger.isEnabled() ) {
             µb.logCosmeticFilters(tabId);
         }
diff --git a/src/js/scriptlet-filtering.js b/src/js/scriptlet-filtering.js
index 075b3e744..5cfd1932a 100644
--- a/src/js/scriptlet-filtering.js
+++ b/src/js/scriptlet-filtering.js
@@ -224,9 +224,8 @@
             return;
         }
 
-        var domain = request.domain,
-            entity = request.entity,
-            entries, entry;
+        let domain = request.domain,
+            entity = request.entity;
 
         // https://github.com/gorhill/uBlock/issues/1954
         // Implicit
@@ -243,13 +242,13 @@
         }
 
         // Explicit
-        entries = [];
+        let entries = [];
         if ( domain !== '' ) {
             scriptletDB.retrieve(domain, hostname, entries);
             scriptletDB.retrieve(entity, entity, entries);
         }
         scriptletDB.retrieve('', hostname, entries);
-        for ( entry of entries ) {
+        for ( let entry of entries ) {
             lookupScriptlet(entry.token, reng, scriptletsRegister);
         }
 
@@ -262,15 +261,15 @@
             scriptletDB.retrieve('!' + entity, entity, entries);
         }
         scriptletDB.retrieve('!', hostname, entries);
-        for ( entry of entries ) {
+        for ( let entry of entries ) {
             exceptionsRegister.add(entry.token);
         }
 
         // Return an array of scriptlets, and log results if needed. 
-        var out = [],
+        let out = [],
             logger = µb.logger.isEnabled() ? µb.logger : null,
             isException;
-        for ( entry of scriptletsRegister ) {
+        for ( let entry of scriptletsRegister ) {
             if ( (isException = exceptionsRegister.has(entry[0])) === false ) {
                 out.push(entry[1]);
             }
@@ -284,6 +283,9 @@
 
         if ( out.length === 0 ) { return; }
 
+        if ( µb.hiddenSettings.debugScriptlets ) {
+            out.unshift('debugger;');
+        }
         return out.join('\n');
     };
 
@@ -303,9 +305,6 @@
         let scriptlets = µb.scriptletFilteringEngine.retrieve(request);
         if ( scriptlets === undefined ) { return; }
         let code = contentscriptCode.assemble(request.hostname, scriptlets);
-        if ( µb.hiddenSettings.debugScriptlets ) {
-            code = 'debugger;\n' + code;
-        }
         chrome.tabs.executeScript(
             details.tabId,
             {
diff --git a/src/js/tab.js b/src/js/tab.js
index 881ce2b3f..56b3ffcfc 100644
--- a/src/js/tab.js
+++ b/src/js/tab.js
@@ -493,7 +493,9 @@ vAPI.tabs.onNavigation = function(details) {
             pageStore.journalAddRootFrame('committed', details.url);
         }
     }
-    µb.scriptletFilteringEngine.injectNow(details);
+    if ( µb.canInjectScriptletsNow ) {
+        µb.scriptletFilteringEngine.injectNow(details);
+    }
 };
 
 /******************************************************************************/