diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 1c00a2dcd27..d65840d153c 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -8047,14 +8047,14 @@ let
   wrapFirefox =
     { browser, browserName ? "firefox", desktopName ? "Firefox", nameSuffix ? ""
     , icon ? "${browser}/lib/${browser.name}/icons/mozicon128.png" }:
+    let
+      cfg = stdenv.lib.attrByPath [ browserName ] {} config;
+      enableAdobeFlash = cfg.enableAdobeFlash or true;
+      enableGnash = cfg.enableGnash or false;
+    in
     import ../applications/networking/browsers/firefox/wrapper.nix {
       inherit stdenv makeWrapper makeDesktopItem browser browserName desktopName nameSuffix icon;
       plugins =
-        let
-          cfg = stdenv.lib.attrByPath [ browserName ] {} config;
-          enableAdobeFlash = cfg.enableAdobeFlash or true;
-          enableGnash = cfg.enableGnash or false;
-        in
          assert !(enableGnash && enableAdobeFlash);
          ([ ]
           ++ lib.optional enableGnash gnash
@@ -8066,7 +8066,7 @@ let
           ++ lib.optional (cfg.enableGoogleTalkPlugin or false) google_talk_plugin
          );
       libs =
-        if config.browserName.enableQuakeLive or false
+        if cfg.enableQuakeLive or false
         then with xlibs; [ stdenv.gcc libX11 libXxf86dga libXxf86vm libXext libXt alsaLib zlib ]
         else [ ];
     };