diff --git a/typescript/types/layout.d.ts b/typescript/types/layout.d.ts
index 58aa98ecd..55ddd7135 100644
--- a/typescript/types/layout.d.ts
+++ b/typescript/types/layout.d.ts
@@ -7,7 +7,7 @@ type ExtractIds<T extends Layout.Hierarchy, Depth extends Prev[number] = 9> =
   [Depth] extends [never]
   ? never
   : (T extends { id?: infer Id extends string }
-    ? { [k in Id]: { -readonly [P in keyof T]: T[P] }  }
+    ? { [k in Id]: { -readonly [P in keyof T]: T[P] extends string ? string : T[P] }  }
     : never)
   |
   (