diff --git a/nixos/modules/services/x11/display-managers/lightdm.nix b/nixos/modules/services/x11/display-managers/lightdm.nix
index 6cccb37a474..508fd665885 100644
--- a/nixos/modules/services/x11/display-managers/lightdm.nix
+++ b/nixos/modules/services/x11/display-managers/lightdm.nix
@@ -97,10 +97,12 @@ in
       # lightdm relaunches itself via just `lightdm`, so needs to be on the PATH
       execCmd = ''
         export PATH=${lightdm}/sbin:$PATH
-        exec ${lightdm}/sbin/lightdm --log-dir=/var/log --run-dir=/run --config=${lightdmConf}
+        exec ${lightdm}/sbin/lightdm --log-dir=/var/log --run-dir=/run
       '';
     };
 
+    environment.etc."lightdm/lightdm.conf".source = lightdmConf;
+
     services.dbus.enable = true;
     services.dbus.packages = [ lightdm ];