diff --git a/packages/core/src/blockchain/storage-layer.ts b/packages/core/src/blockchain/storage-layer.ts
index 1df32859..5c75b553 100644
--- a/packages/core/src/blockchain/storage-layer.ts
+++ b/packages/core/src/blockchain/storage-layer.ts
@@ -107,7 +107,7 @@ export class RemoteStorageLayer implements StorageLayerProvider {
 }
 
 export class StorageLayer implements StorageLayerProvider {
-  readonly #store: Record<string, StorageValue | Promise<StorageValue>> = {}
+  readonly #store: Map<string, StorageValue | Promise<StorageValue>> = new Map()
   readonly #keys: string[] = []
   readonly #deletedPrefix: string[] = []
   #parent?: StorageLayerProvider
@@ -134,8 +134,8 @@ export class StorageLayer implements StorageLayerProvider {
   }
 
   async get(key: string, cache: boolean): Promise<StorageValue | undefined> {
-    if (key in this.#store) {
-      return this.#store[key]
+    if (this.#store.has(key)) {
+      return this.#store.get(key)
     }
 
     if (this.#deletedPrefix.some((dp) => key.startsWith(dp))) {
@@ -145,7 +145,7 @@ export class StorageLayer implements StorageLayerProvider {
     if (this.#parent) {
       const val = this.#parent.get(key, false)
       if (cache) {
-        this.#store[key] = val
+        this.#store.set(key, val)
       }
       return val
     }
@@ -156,24 +156,24 @@ export class StorageLayer implements StorageLayerProvider {
   set(key: string, value: StorageValue): void {
     switch (value) {
       case StorageValueKind.Deleted:
-        this.#store[key] = StorageValueKind.Deleted
+        this.#store.set(key, StorageValueKind.Deleted)
         this.#removeKey(key)
         break
       case StorageValueKind.DeletedPrefix:
         this.#deletedPrefix.push(key)
         for (const k of this.#keys) {
           if (k.startsWith(key)) {
-            this.#store[k] = StorageValueKind.Deleted
+            this.#store.set(k, StorageValueKind.Deleted)
             this.#removeKey(k)
           }
         }
         break
       case undefined:
-        delete this.#store[key]
+        this.#store.delete(key)
         this.#removeKey(key)
         break
       default:
-        this.#store[key] = value
+        this.#store.set(key, value)
         this.#addKey(key)
         break
     }
@@ -195,7 +195,7 @@ export class StorageLayer implements StorageLayerProvider {
       into.set(deletedPrefix, StorageValueKind.DeletedPrefix)
     }
 
-    for (const [key, value] of Object.entries(this.#store)) {
+    for (const [key, value] of this.#store) {
       into.set(key, await value)
     }
 
@@ -212,10 +212,10 @@ export class StorageLayer implements StorageLayerProvider {
     if (!this.#deletedPrefix.some((dp) => startKey.startsWith(dp))) {
       const remote = (await this.#parent?.getKeysPaged(prefix, pageSize, startKey)) ?? []
       for (const key of remote) {
-        if (this.#deletedPrefix.some((dp) => key.startsWith(dp))) {
+        if (this.#store.get(key) === StorageValueKind.Deleted) {
           continue
         }
-        if (this.#store[key] === StorageValueKind.Deleted) {
+        if (this.#deletedPrefix.some((dp) => key.startsWith(dp))) {
           continue
         }
         this.#addKey(key)
@@ -242,7 +242,7 @@ export class StorageLayer implements StorageLayerProvider {
    * Merge the storage layer into the given object, can be used to get sotrage diff.
    */
   async mergeInto(into: Record<string, string | null>) {
-    for (const [key, maybeValue] of Object.entries(this.#store)) {
+    for (const [key, maybeValue] of this.#store) {
       const value = await maybeValue
       if (value === StorageValueKind.Deleted) {
         into[key] = null