diff --git a/nixos/modules/services/x11/desktop-managers/kde4.nix b/nixos/modules/services/x11/desktop-managers/kde4.nix
index 5c783fdbcedd..f7579fce7b5a 100644
--- a/nixos/modules/services/x11/desktop-managers/kde4.nix
+++ b/nixos/modules/services/x11/desktop-managers/kde4.nix
@@ -161,6 +161,10 @@ in
 
     environment.pathsToLink = [ "/share" ];
 
+    environment.profileRelativeEnvVars = mkIf (lib.elem "gstreamer" cfg.phononBackends) {
+      GST_PLUGIN_SYSTEM_PATH = [ "/lib/gstreamer-0.10" ];
+    };
+
     environment.etc = singleton
       { source = "${pkgs.xkeyboard_config}/etc/X11/xkb";
         target = "X11/xkb";