diff --git a/modules/users.nix b/modules/users.nix
index 04e8e84a..20ee43ee 100644
--- a/modules/users.nix
+++ b/modules/users.nix
@@ -213,7 +213,7 @@ in
     };
 
     sane.defaultUser = mkOption {
-      type = types.nullOr types.string;
+      type = types.nullOr types.str;
       default = null;
       description = ''
         the name of the default user.
diff --git a/modules/warnings.nix b/modules/warnings.nix
index f0baf1fd..6f2e0a38 100644
--- a/modules/warnings.nix
+++ b/modules/warnings.nix
@@ -2,7 +2,7 @@
 {
   options = with lib; {
     sane.silencedWarnings = mkOption {
-      type = types.listOf types.string;
+      type = types.listOf types.str;
       default = [];
       description = ''
         list of `config.warnings` values you want to ignore, verbatim.