diff --git a/pkgs/desktops/kde-4.8/kde-package/default.nix b/pkgs/desktops/kde-4.8/kde-package/default.nix
index da6440b58fa..cd2860920d6 100644
--- a/pkgs/desktops/kde-4.8/kde-package/default.nix
+++ b/pkgs/desktops/kde-4.8/kde-package/default.nix
@@ -51,7 +51,7 @@ rec {
           "-DBUILD_${subdir}=TRUE"
         ] ++ cmakeFlags;
       meta = defMeta // meta;
-      enableParallelBuilding = true;
+      enableParallelBuilding = module.enableParallelBuilding or true;
     } // (removeAttrs a [ "meta" "name" "cmakeFlags" ]));
 
   # A KDE monolithic module
diff --git a/pkgs/desktops/kde-4.8/kde-workspace.nix b/pkgs/desktops/kde-4.8/kde-workspace.nix
index 97192e55be3..394cd550b96 100644
--- a/pkgs/desktops/kde-4.8/kde-workspace.nix
+++ b/pkgs/desktops/kde-4.8/kde-workspace.nix
@@ -28,6 +28,8 @@ kde {
        --replace /usr/share/X11 ${xkeyboard_config}/etc/X11
    '';
 
+  enableParallelBuilding = false; # frequent problems on Hydra
+
   meta = {
     description = "KDE workspace components such as Plasma, Kwin and System Settings";
     license = "GPLv2";