diff --git a/nixos/modules/programs/plotinus.nix b/nixos/modules/programs/plotinus.nix
index e3549c79588b..2c90a41ba029 100644
--- a/nixos/modules/programs/plotinus.nix
+++ b/nixos/modules/programs/plotinus.nix
@@ -30,7 +30,7 @@ in
   ###### implementation
 
   config = mkIf cfg.enable {
-    environment.variables.XDG_DATA_DIRS = [ "${pkgs.plotinus}/share/gsettings-schemas/${pkgs.plotinus.name}" ];
+    environment.sessionVariables.XDG_DATA_DIRS = [ "${pkgs.plotinus}/share/gsettings-schemas/${pkgs.plotinus.name}" ];
     environment.variables.GTK3_MODULES = [ "${pkgs.plotinus}/lib/libplotinus.so" ];
   };
 }