diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index 6d1ad766d684..4a623fda9bec 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -179,7 +179,8 @@ stdenv.mkDerivation ({
   configurePhase = ''
     runHook preConfigure
 
-    export buildRoot=$(mktemp -d)
+    export buildRoot=$TMPDIR/kernel-buildroot
+    mkdir -p $buildRoot
 
     echo "manual-config configurePhase buildRoot=$buildRoot pwd=$PWD"