diff --git a/pkgs/development/compilers/gcc-4.5/default.nix b/pkgs/development/compilers/gcc-4.5/default.nix
index 1e4a98805ba..950243bebe7 100644
--- a/pkgs/development/compilers/gcc-4.5/default.nix
+++ b/pkgs/development/compilers/gcc-4.5/default.nix
@@ -147,6 +147,8 @@ stdenv.mkDerivation ({
 
   postPatch =
     if (stdenv.system == "i586-pc-gnu"
+        || (libcCross != null                  # e.g., building `gcc.hostDrv'
+            && libcCross.crossConfig == "i586-pc-gnu")
         || (cross != null && cross.config == "i586-pc-gnu"
             && libcCross != null))
     then