diff --git a/nix/culr-module.nix b/nix/culr-module.nix
index 91f12c0..b46aa6c 100644
--- a/nix/culr-module.nix
+++ b/nix/culr-module.nix
@@ -4,7 +4,7 @@
   config,
   ...
 }: let
-  inherit (lib) mkIf mkEnableOption mkOption types;
+  inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep;
   cfg = config.programs.culr;
 in {
   options.programs.culr = {
@@ -24,8 +24,8 @@ in {
   config = mkIf cfg.enable {
     environment.systemPackages = let inherit (pkgs) culr; in [culr];
     environment.sessionVariables = {
-      CULR_PATTERN = mkIf (cfg.pattern != []) cfg.pattern;
-      CULR_PALETTE = mkIf (cfg.palette != []) cfg.palette;
+      CULR_PATTERN = mkIf (cfg.pattern != []) (concatStringsSep ";" cfg.pattern);
+      CULR_PALETTE = mkIf (cfg.palette != []) (concatStringsSep ";" cfg.palette);
     };
   };
 }