diff --git a/mkosi.extra/usr/share/firefox-config/policies.json b/mkosi.extra/usr/share/firefox-config/policies.json
index dc1b73b..63fcde5 100644
--- a/mkosi.extra/usr/share/firefox-config/policies.json
+++ b/mkosi.extra/usr/share/firefox-config/policies.json
@@ -1,7 +1,11 @@
 {
   "policies": {
-    "Extensions": {
-      "Install": ["https://addons.mozilla.org/firefox/downloads/latest/plasma-integration/"]
+    "ExtensionSettings": {
+      "plasma-browser-integration@kde.org": {
+        "installation_mode": "normal_installed",
+        "install_url": "https://addons.mozilla.org/firefox/downloads/latest/plasma-integration/latest.xpi",
+        "private_browsing": true
+      }
     }
   }
 }