diff --git a/src/client/config.mli b/src/client/config.mli
index 13bb52d6..f3a4e6ec 100644
--- a/src/client/config.mli
+++ b/src/client/config.mli
@@ -105,13 +105,13 @@ module type ENV = sig
       more specific field like so:
 
       {[
-        type extended_confg =
-          { new_field: string
-          ; common: t
-          }
+        type extended_config = {
+          new_field: string;
+          common: t;
+        }
 
-        let make : (new_field:string -> unit) make =
-          Env.make (fun common ~new_field () -> {new_field; common})
+        let make : (new_field:string -> unit -> extended_config) make =
+          Env.make (fun common ~new_field () -> { new_field; common })
 
         let _example : extended_config =
           make ~new_field:"foo" ~url_traces:"foo/bar" ~debug:true ()