diff --git a/pkgs/applications/networking/browsers/opera/default.nix b/pkgs/applications/networking/browsers/opera/default.nix
index 6df914cb7759..da812d3933ae 100644
--- a/pkgs/applications/networking/browsers/opera/default.nix
+++ b/pkgs/applications/networking/browsers/opera/default.nix
@@ -2,7 +2,7 @@
 , makeDesktopItem
 }:
 
-assert stdenv.isLinux;
+assert stdenv.isLinux && stdenv.gcc.gcc != null;
 
 stdenv.mkDerivation rec {
   name = "opera-10.00";
diff --git a/pkgs/misc/drivers/gutenprint/bin.nix b/pkgs/misc/drivers/gutenprint/bin.nix
index 91628e90dfab..aef8c239caf0 100644
--- a/pkgs/misc/drivers/gutenprint/bin.nix
+++ b/pkgs/misc/drivers/gutenprint/bin.nix
@@ -1,6 +1,6 @@
 args: with args;
 
-assert stdenv.isLinux;
+assert stdenv.system == "x86_64-linux";
 
 /* usage: (sorry, its still impure but works!)