diff --git a/src/vanilla/utils/proxyMap.ts b/src/vanilla/utils/proxyMap.ts
index ac4c58c6..593112ef 100644
--- a/src/vanilla/utils/proxyMap.ts
+++ b/src/vanilla/utils/proxyMap.ts
@@ -66,7 +66,7 @@ export function proxyMap<K, V>(entries?: Iterable<[K, V]> | undefined | null) {
       const map = getMapForThis(this)
       const k = maybeProxify(key)
       const exists = map.has(k)
-      if (!exists && !isProxy(this)) {
+      if (!exists) {
         // eslint-disable-next-line @typescript-eslint/no-unused-expressions
         this.index
       }
diff --git a/src/vanilla/utils/proxySet.ts b/src/vanilla/utils/proxySet.ts
index 4b8ce294..ecdddcf7 100644
--- a/src/vanilla/utils/proxySet.ts
+++ b/src/vanilla/utils/proxySet.ts
@@ -58,7 +58,7 @@ export function proxySet<T>(initialValues?: Iterable<T> | null) {
       const map = getMapForThis(this)
       const value = maybeProxify(v)
       const exists = map.has(value)
-      if (!exists && !isProxy(this)) {
+      if (!exists) {
         // eslint-disable-next-line @typescript-eslint/no-unused-expressions
         this.index
       }