diff --git a/nix/culr-module.nix b/nix/culr-module.nix
index 427643e..389d99f 100644
--- a/nix/culr-module.nix
+++ b/nix/culr-module.nix
@@ -10,12 +10,12 @@ in {
   options.programs.culr = {
     enable = mkEnableOption "culr";
     pattern = mkOption {
-      type = with types; either (listOf int) str;
+      type = with types; nullOr (either (listOf int) str);
       default = null;
       description = "colourising pattern";
     };
     palette = mkOption {
-      type = with types; listOf str;
+      type = with types; nullOr (listOf str);
       default = null;
       description = "palette to use in comma separated RGB hex eg. #0f0f0f";
     };