diff --git a/krebs/3modules/Reaktor.nix b/krebs/3modules/Reaktor.nix
index 308c6d41d..2a035d7be 100644
--- a/krebs/3modules/Reaktor.nix
+++ b/krebs/3modules/Reaktor.nix
@@ -17,7 +17,7 @@ let
 
       nickname = mkOption {
         default = config.krebs.build.host.name + "|r";
-        type = types.string;
+        type = types.str;
         description = ''
           The nick name of the irc bot.
           Defaults to {hostname}|r
@@ -47,7 +47,7 @@ let
 
       extraConfig = mkOption {
         default = "";
-        type = types.string;
+        type = types.str;
         description = ''
           configuration appended to the default or overridden configuration
         '';