diff --git a/nixos/modules/programs/regreet.nix b/nixos/modules/programs/regreet.nix
index 151ad3a623ca..800642e2087a 100644
--- a/nixos/modules/programs/regreet.nix
+++ b/nixos/modules/programs/regreet.nix
@@ -159,7 +159,10 @@ in
 
     environment.etc = {
       "greetd/regreet.css" =
-        if lib.isPath cfg.extraCss then { source = cfg.extraCss; } else { text = cfg.extraCss; };
+        if lib.isPath cfg.extraCss || lib.isStorePath cfg.extraCss then
+          { source = cfg.extraCss; }
+        else
+          { text = cfg.extraCss; };
 
       "greetd/regreet.toml".source =
         if lib.isPath cfg.settings then