diff --git a/packages/genodelabs/default.nix b/packages/genodelabs/default.nix
index d6415cf..7b2abe3 100644
--- a/packages/genodelabs/default.nix
+++ b/packages/genodelabs/default.nix
@@ -122,7 +122,7 @@ let
   ports =
     lib.mapAttrs preparePort (import ./ports.nix { inherit buildPackages; });
 
-  toolchain' = buildPackages.gcc8Stdenv.mkDerivation rec {
+  toolchain' = buildPackages.stdenv.mkDerivation rec {
     pname = "toolchain";
     inherit (genodeSources) src version;
 
@@ -154,11 +154,14 @@ let
       export CONTRIB_DIR=$GENODE_DIR/contrib
       export BUILD_DIR=$GENODE_DIR/build
       echo true > tool/ports/prepare_port
-      patchShebangs tool
       mkdir $CONTRIB_DIR; ${linkPorts}
+      patchShebangs tool $CONTRIB_DIR
       runHook postConfigure
     '';
 
+    enableParallelBuilding = false;
+    hardeningDisable = [ "format" ];
+
     makefile = "tool/tool_chain";
     buildFlags = let
       arch = with platform;
@@ -170,7 +173,13 @@ let
           "aarch64"
         else
           throw "unknown toolchain for platform ${platform.system}";
-    in [ "INSTALL_LOCATION=$out" "VERBOSE=" arch ];
+    in [
+      "INSTALL_LOCATION=$out"
+      "MAKE_JOBS=$${NIX_BUILD_CORES}"
+      "SUDO="
+      "VERBOSE="
+      arch
+    ];
 
     dontInstall = true;
   };