diff --git a/pkgs/applications/networking/browsers/firefox-bin/default.nix b/pkgs/applications/networking/browsers/firefox-bin/default.nix
index 7e92df163af..91aee7b1e8a 100644
--- a/pkgs/applications/networking/browsers/firefox-bin/default.nix
+++ b/pkgs/applications/networking/browsers/firefox-bin/default.nix
@@ -82,7 +82,7 @@ stdenv.mkDerivation {
 
   src = fetchurl { inherit (source) url sha512; };
 
-  phases = [ "unpackPhase" "installPhase" "fixupPhase" ];
+  phases = [ "unpackPhase" "patchPhase" "installPhase" "fixupPhase" ];
 
   libPath = stdenv.lib.makeLibraryPath
     [ stdenv.cc.cc
@@ -142,8 +142,8 @@ stdenv.mkDerivation {
   dontPatchELF = true;
 
   patchPhase = ''
-    sed -i -e '/^pref("app.update.channel",/d' defaults/pref/channel-prefs.js
-    echo 'pref("app.update.channel", "non-existing-channel")' >> defaults/pref/channel-prefs.js
+    # Don't download updates from Mozilla directly
+    echo 'pref("app.update.auto", "false");' >> defaults/pref/channel-prefs.js
   '';
 
   installPhase =