diff --git a/pkgs/top-level/release.nix b/pkgs/top-level/release.nix
index 32494f64ad2..11102f89155 100644
--- a/pkgs/top-level/release.nix
+++ b/pkgs/top-level/release.nix
@@ -359,7 +359,7 @@ let
       };
 
       firefox36Pkgs.firefox = linux;
-      firefox21Pkgs.firefox = linux;
+      firefox20Pkgs.firefox = linux;
 
       gnome = {
         gnome_panel = linux;