diff --git a/nix/culr-module.nix b/nix/culr-module.nix
index b46aa6c..50261a8 100644
--- a/nix/culr-module.nix
+++ b/nix/culr-module.nix
@@ -4,13 +4,13 @@
   config,
   ...
 }: let
-  inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep;
+  inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep typeOf;
   cfg = config.programs.culr;
 in {
   options.programs.culr = {
     enable = mkEnableOption "culr";
     pattern = mkOption {
-      type = with types; listOf int;
+      type = with types; either str (listOf int);
       default = [];
       description = "colourising pattern";
     };
@@ -24,7 +24,15 @@ in {
   config = mkIf cfg.enable {
     environment.systemPackages = let inherit (pkgs) culr; in [culr];
     environment.sessionVariables = {
-      CULR_PATTERN = mkIf (cfg.pattern != []) (concatStringsSep ";" cfg.pattern);
+      CULR_PATTERN = let
+        serialise = {
+          list = list: concatStringsSep ";";
+          str = s: s;
+        };
+      in
+        mkIf (cfg.pattern != "" && cfg.pattern != [])
+        serialise.${typeOf cfg.pattern}
+        cfg.pattern;
       CULR_PALETTE = mkIf (cfg.palette != []) (concatStringsSep ";" cfg.palette);
     };
   };