diff --git a/pkgs/applications/networking/browsers/firefox/default.nix b/pkgs/applications/networking/browsers/firefox/default.nix
index f02ebd95a062..7a8080ad3d51 100644
--- a/pkgs/applications/networking/browsers/firefox/default.nix
+++ b/pkgs/applications/networking/browsers/firefox/default.nix
@@ -4,7 +4,7 @@
 assert pkgconfig != null && gtk != null && perl != null
   && zip != null && libIDL != null;
 
-assert libIDL.glib == gtk.glib;
+# !!! assert libIDL.glib == gtk.glib;
 
 stdenv.mkDerivation {
   name = "firefox-0.8";
@@ -15,5 +15,5 @@ stdenv.mkDerivation {
     md5 = "cdc85152f4219bf3e3f1a8dc46e04654";
   };
 
-  buildInputs = [pkgconfig, gtk, perl, zip, libIDL];
+  buildInputs = [pkgconfig gtk perl zip libIDL];
 }
diff --git a/pkgs/development/libraries/freedesktop/libXt/default.nix b/pkgs/development/libraries/freedesktop/libXt/default.nix
index b00c0215cace..a8fc2352355d 100644
--- a/pkgs/development/libraries/freedesktop/libXt/default.nix
+++ b/pkgs/development/libraries/freedesktop/libXt/default.nix
@@ -6,7 +6,8 @@ stdenv.mkDerivation {
     url = http://freedesktop.org/~xlibs/release/xlibs-1.0/libXt-0.1.4.tar.bz2;
     md5 = "32b6528c9deb058d1a9ed17ffa848df8";
   };
-  buildInputs = [pkgconfig libX11 libSM patch];
+  buildInputs = [pkgconfig libX11 patch];
+  propagatedBuildInputs = [libSM];
   # This patch should become unnecessary soon; already been fixed in CVS.
   patches = [./patch];
 }