diff --git a/platform/mv3/extension/js/background.js b/platform/mv3/extension/js/background.js
index 547f573e2..45a879af2 100644
--- a/platform/mv3/extension/js/background.js
+++ b/platform/mv3/extension/js/background.js
@@ -50,7 +50,7 @@ import {
     setFilteringMode,
     getDefaultFilteringMode,
     setDefaultFilteringMode,
-    syncWithDemotedOrigins,
+    syncWithBrowserPermissions,
 } from './mode-manager.js';
 
 /******************************************************************************/
@@ -154,13 +154,15 @@ function hasOmnipotence() {
     });
 }
 
-function onPermissionsRemoved(permissions) {
-    if ( permissions.origins?.includes('<all_urls>') ) {
+async function onPermissionsRemoved() {
+    const beforeMode = await getDefaultFilteringMode();
+    const modified = await syncWithBrowserPermissions();
+    if ( modified === false ) { return; }
+    const afterMode = await getDefaultFilteringMode();
+    if ( beforeMode > 1 && afterMode <= 1 ) {
         updateDynamicRules();
     }
-    syncWithDemotedOrigins(permissions.origins).then(( ) => {
-        registerInjectables(permissions.origins);
-    });
+    registerInjectables();
 }
 
 /******************************************************************************/
@@ -287,6 +289,9 @@ async function start() {
         });
     }
 
+    // Permissions may have been removed while the extension was disabled
+    await onPermissionsRemoved();
+
     // Unsure whether the browser remembers correctly registered css/scripts
     // after we quit the browser. For now uBOL will check unconditionally at
     // launch time whether content css/scripts are properly registered.
@@ -307,7 +312,9 @@ async function start() {
 
     runtime.onMessage.addListener(onMessage);
 
-    browser.permissions.onRemoved.addListener(onPermissionsRemoved);
+    browser.permissions.onRemoved.addListener(
+        ( ) => { onPermissionsRemoved(); }
+    );
 
     if ( rulesetConfig.firstRun ) {
         runtime.openOptionsPage();
diff --git a/platform/mv3/extension/js/mode-manager.js b/platform/mv3/extension/js/mode-manager.js
index 0b61c4667..e2a94a973 100644
--- a/platform/mv3/extension/js/mode-manager.js
+++ b/platform/mv3/extension/js/mode-manager.js
@@ -25,7 +25,10 @@
 
 /******************************************************************************/
 
-import { dnr } from './ext.js';
+import {
+    browser,
+    dnr,
+} from './ext.js';
 
 import {
     hostnamesFromMatches,
@@ -326,22 +329,31 @@ async function setDefaultFilteringMode(afterLevel) {
 
 /******************************************************************************/
 
-async function syncWithDemotedOrigins(demotedOrigins) {
-    const demotedHostnames = new Set(hostnamesFromMatches(demotedOrigins));
-    if ( demotedHostnames.has('all-urls') ) {
+async function syncWithBrowserPermissions() {
+    const permissions = await browser.permissions.getAll();
+    const allowedHostnames = new Set(hostnamesFromMatches(permissions.origins || []));
+    const beforeMode = await getDefaultFilteringMode();
+    let modified = false;
+    if ( beforeMode > 1 && allowedHostnames.has('all-urls') === false ) {
         await setDefaultFilteringMode(1);
+        modified = true;
     }
+    const afterMode = await getDefaultFilteringMode();
+    if ( afterMode > 1 ) { return false; }
     const filteringModes = await getFilteringModeDetails();
     const { extendedSpecific, extendedGeneric } = filteringModes;
     for ( const hn of extendedSpecific ) {
-        if ( demotedHostnames.has(hn) === false ) { continue; }
+        if ( allowedHostnames.has(hn) ) { continue; }
         extendedSpecific.delete(hn);
+        modified = true;
     }
     for ( const hn of extendedGeneric ) {
-        if ( demotedHostnames.has(hn) === false ) { continue; }
+        if ( allowedHostnames.has(hn) ) { continue; }
         extendedGeneric.delete(hn);
+        modified = true;
     }
-    return setFilteringModeDetails(filteringModes);
+    await setFilteringModeDetails(filteringModes);
+    return modified;
 }
 
 /******************************************************************************/
@@ -362,5 +374,5 @@ export {
     setDefaultFilteringMode,
     getFilteringModeDetails,
     getAllTrustedSiteDirectives,
-    syncWithDemotedOrigins,
+    syncWithBrowserPermissions,
 };
diff --git a/platform/mv3/scriptlets/no-windowopen-if.js b/platform/mv3/scriptlets/no-windowopen-if.js
index 9e65cc422..e1b30241c 100644
--- a/platform/mv3/scriptlets/no-windowopen-if.js
+++ b/platform/mv3/scriptlets/no-windowopen-if.js
@@ -28,8 +28,8 @@
 
 /******************************************************************************/
 
-/// name no-windowOpen-if
-/// alias no-windowopen-if
+/// name no-windowopen-if
+/// alias no-windowOpen-if
 /// alias nowoif
 
 /******************************************************************************/