diff --git a/module.nix b/module.nix
index 4b6f56c..a97c3c4 100644
--- a/module.nix
+++ b/module.nix
@@ -17,12 +17,12 @@ in {
     };
 
     group = lib.mkOption {
-      type = lib.types.string;
+      type = lib.types.str;
       default = "matrixoidc";
     };
 
     args = lib.mkOption {
-      type = lib.types.string;
+      type = lib.types.separatedString " ";
       default = "";
     };
   };