diff --git a/packages/reactivity/src/reactive.ts b/packages/reactivity/src/reactive.ts
index 92fd172707b..9cce2ea0e64 100644
--- a/packages/reactivity/src/reactive.ts
+++ b/packages/reactivity/src/reactive.ts
@@ -132,6 +132,8 @@ export type DeepReadonly<T> = T extends Builtin
   ? WeakSet<DeepReadonly<U>>
   : T extends Promise<infer U>
   ? Promise<DeepReadonly<U>>
+  : T extends Ref<infer U>
+  ? Ref<DeepReadonly<U>>
   : T extends {}
   ? { readonly [K in keyof T]: DeepReadonly<T[K]> }
   : Readonly<T>