diff --git a/packages/private/src/types.ts b/packages/private/src/types.ts
index e61803968..15756e3f4 100644
--- a/packages/private/src/types.ts
+++ b/packages/private/src/types.ts
@@ -11,7 +11,7 @@ type Primitive = string | boolean | number | null | undefined;
 export type MapLeafNodes<Obj, LeafType> = {
   [Prop in keyof Obj]: Obj[Prop] extends Primitive
     ? LeafType
-    : Obj[Prop] extends Record<string | number, any>
+    : Obj[Prop] extends Record<string | number, any> | undefined
     ? MapLeafNodes<Obj[Prop], LeafType>
     : never;
 };