diff --git a/pkgs/applications/kde/mbox-importer.nix b/pkgs/applications/kde/mbox-importer.nix
index aa637d440bd9..0704003353ae 100644
--- a/pkgs/applications/kde/mbox-importer.nix
+++ b/pkgs/applications/kde/mbox-importer.nix
@@ -14,7 +14,4 @@ mkDerivation {
   buildInputs = [
     akonadi akonadi-search kconfig kservice kio mailcommon mailimporter messagelib
   ];
-  preHook = ''
-    set -x
-  '';
 }