diff --git a/pkgs/misc/screensavers/xlockmore/default.nix b/pkgs/misc/screensavers/xlockmore/default.nix
index ddb4235c5db..b9294e294e9 100644
--- a/pkgs/misc/screensavers/xlockmore/default.nix
+++ b/pkgs/misc/screensavers/xlockmore/default.nix
@@ -30,6 +30,8 @@ stdenv.mkDerivation rec {
       configureFlags+=" --enable-appdefaultdir=$out/share/X11/app-defaults"
     '';
 
+  hardeningDisable = [ "format" ]; # no build output otherwise
+
   meta = with lib; {
     description = "Screen locker for the X Window System";
     homepage = http://sillycycle.com/xlockmore.html;