diff --git a/pkgs/tools/misc/calamares/default.nix b/pkgs/tools/misc/calamares/default.nix
index d3a1ea13ff85..7565aa018253 100644
--- a/pkgs/tools/misc/calamares/default.nix
+++ b/pkgs/tools/misc/calamares/default.nix
@@ -57,7 +57,7 @@ mkDerivation rec {
 
   postPatch = ''
     # Run calamares without root. Other patches make it functional as a normal user
-    sed -e "s,pkexec calamares,calamares," \
+    sed -e "s,pkexec calamares,calamares -D6," \
         -i calamares.desktop
 
     sed -e "s,X-AppStream-Ignore=true,&\nStartupWMClass=calamares," \