diff --git a/packages/ublock-origin.nix b/packages/ublock-origin.nix
index 870a1186..c5a45ad8 100644
--- a/packages/ublock-origin.nix
+++ b/packages/ublock-origin.nix
@@ -2,6 +2,8 @@
   lib,
   stdenvNoCC,
   fetchurl,
+  unzip,
+  zip,
 }:
 
 stdenvNoCC.mkDerivation (finalAttrs: {
@@ -15,10 +17,27 @@ stdenvNoCC.mkDerivation (finalAttrs: {
 
   dontUnpack = true;
 
+  nativeBuildInputs = [
+    unzip
+    zip
+  ];
+
+  postPatch = ''
+    unzip "$src"
+
+    substituteInPlace ./js/vapi-background-ext.js \
+      --replace-fail "browser.dns instanceof Object" "false"
+
+    substituteInPlace ./js/background.js \
+      --replace-fail "cnameUncloakEnabled: true" "cnameUncloakEnabled: false"
+
+    zip -x env-vars -r ublock-origin.xpi *
+  '';
+
   installPhase = ''
     runHook preInstall
 
-    install -Dm644 "$src" "$out/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/uBlock0@raymondhill.net.xpi"
+    install -Dm644 ublock-origin.xpi "$out/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/uBlock0@raymondhill.net.xpi"
 
     runHook postInstall
   '';