diff --git a/advanced/part1/src/Viewer/Cred.elm b/advanced/part1/src/Viewer/Cred.elm
index 50151f1..4cb3508 100644
--- a/advanced/part1/src/Viewer/Cred.elm
+++ b/advanced/part1/src/Viewer/Cred.elm
@@ -11,17 +11,17 @@ import Username exposing (Username)
 -- TYPES
 
 
-type alias Cred =
-    -- 👉 TODO make Cred an opaque type, then fix the resulting compiler errors.
-    -- Afterwards, it should no longer be possible for any other module to access
-    -- this `token` vale directly!
-    --
-    -- 💡 HINT: Other modules still depend on being able to access the
-    -- `username` value. Expand this module's API to expose a new way for them
-    -- to access the `username` without also giving them access to `token`.
-    { username : Username
-    , token : String
-    }
+type Cred
+    = Cred Username String
+
+
+
+-- INFO
+
+
+username : Cred -> Username
+username (Cred uname _) =
+    uname
 
 
 
@@ -40,14 +40,14 @@ decoder =
 
 
 encodeToken : Cred -> Value
-encodeToken cred =
-    Encode.string cred.token
+encodeToken (Cred _ token) =
+    Encode.string token
 
 
 addHeader : Cred -> RequestBuilder a -> RequestBuilder a
-addHeader cred builder =
+addHeader (Cred _ token) builder =
     builder
-        |> withHeader "authorization" ("Token " ++ cred.token)
+        |> withHeader "authorization" ("Token " ++ token)
 
 
 addHeaderIfAvailable : Maybe Cred -> RequestBuilder a -> RequestBuilder a