diff --git a/deno.json b/deno.json
index 5167da7..68666fd 100644
--- a/deno.json
+++ b/deno.json
@@ -1,6 +1,6 @@
 {
   "name": "@izure/serializable-bptree",
-  "version": "5.0.3",
+  "version": "5.0.4",
   "description": "Store the B+tree flexibly, not only in-memory.",
   "author": "izure1 <admin@izure.org>",
   "license": "MIT",
diff --git a/package.json b/package.json
index de27986..768cadc 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "serializable-bptree",
-  "version": "5.0.3",
+  "version": "5.0.4",
   "description": "Store the B+tree flexibly, not only in-memory.",
   "types": "./dist/types/index.d.ts",
   "main": "./dist/cjs/index.cjs",
diff --git a/src/BPTreeAsync.ts b/src/BPTreeAsync.ts
index cf5a247..7954719 100644
--- a/src/BPTreeAsync.ts
+++ b/src/BPTreeAsync.ts
@@ -164,11 +164,11 @@ export class BPTreeAsync<K, V> extends BPTree<K, V> {
       this.root = await this.getNode(keys[0])
       this.root.parent = null
       this.strategy.head.root = this.root.id
-      this._strategyDirty = true
       this.bufferForNodeUpdate(this.root)
       return
     }
     else if (this.root === node) {
+      this.bufferForNodeUpdate(this.root)
       return
     }
     else if (
@@ -370,7 +370,6 @@ export class BPTreeAsync<K, V> extends BPTree<K, V> {
       const root = await this._createNode(false, [node.id, pointer.id], [value])
       this.root = root
       this.strategy.head.root = root.id
-      this._strategyDirty = true
       node.parent = root.id
       pointer.parent = root.id
       this.bufferForNodeCreate(root)
diff --git a/src/BPTreeSync.ts b/src/BPTreeSync.ts
index 531011e..7ebd25d 100644
--- a/src/BPTreeSync.ts
+++ b/src/BPTreeSync.ts
@@ -164,11 +164,11 @@ export class BPTreeSync<K, V> extends BPTree<K, V> {
       this.root = this.getNode(keys[0])
       this.root.parent = null
       this.strategy.head.root = this.root.id
-      this._strategyDirty = true
       this.bufferForNodeUpdate(this.root)
       return
     }
     else if (this.root === node) {
+      this.bufferForNodeUpdate(this.root)
       return
     }
     else if (
@@ -370,7 +370,6 @@ export class BPTreeSync<K, V> extends BPTree<K, V> {
       const root = this._createNode(false, [node.id, pointer.id], [value])
       this.root = root
       this.strategy.head.root = root.id
-      this._strategyDirty = true
       node.parent = root.id
       pointer.parent = root.id
       this.bufferForNodeCreate(root)
diff --git a/src/base/BPTree.ts b/src/base/BPTree.ts
index 02fd821..14aa3ce 100644
--- a/src/base/BPTree.ts
+++ b/src/base/BPTree.ts
@@ -254,14 +254,23 @@ export abstract class BPTree<K, V> {
   }
 
   protected bufferForNodeCreate(node: BPTreeUnknownNode<K, V>): void {
+    if (node.id === this.root.id) {
+      this._strategyDirty = true
+    }
     this._nodeCreateBuffer.set(node.id, node)
   }
 
   protected bufferForNodeUpdate(node: BPTreeUnknownNode<K, V>): void {
+    if (node.id === this.root.id) {
+      this._strategyDirty = true
+    }
     this._nodeUpdateBuffer.set(node.id, node)
   }
 
   protected bufferForNodeDelete(node: BPTreeUnknownNode<K, V>): void {
+    if (node.id === this.root.id) {
+      this._strategyDirty = true
+    }
     this._nodeDeleteBuffer.set(node.id, node)
   }