diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e049a805893a..0fa170f3605e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1558,10 +1558,10 @@ let pkgs = rec {
     haddock = haddockboot;
   };
 
-  ghc69snapshot = import ../development/compilers/ghc-6.8/head.nix {
+  ghc69snapshot = lowPrio (import ../development/compilers/ghc-6.8/head.nix {
     inherit fetchurl stdenv readline perl gmp ncurses m4;
     ghc = ghc683;
-  };
+  });
 
   ghc661 = import ../development/compilers/ghc-6.6.1 {
     inherit fetchurl stdenv readline perl58 gmp ncurses m4;