diff --git a/package.json b/package.json
index 6637dfa..799d6fa 100644
--- a/package.json
+++ b/package.json
@@ -50,6 +50,7 @@
     "jotai": "^2.13.1",
     "lucide-react": "^0.542.0",
     "next": "15.5.2",
+    "prexit": "^2.3.0",
     "react": "^19.1.1",
     "react-dom": "^19.1.1",
     "react-error-boundary": "^6.0.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 78a72ba..6badbfa 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -56,6 +56,9 @@ importers:
       next:
         specifier: 15.5.2
         version: 15.5.2(react-dom@19.1.1(react@19.1.1))(react@19.1.1)
+      prexit:
+        specifier: ^2.3.0
+        version: 2.3.0
       react:
         specifier: ^19.1.1
         version: 19.1.1
@@ -2681,6 +2684,10 @@ packages:
     resolution: {integrity: sha512-4yf0QO/sllf/1zbZWYnvWw3NxCQwLXKzIj0G849LSufP15BXKM0rbD2Z3wVnkMfjdn/CB0Dpp444gYAACdsplg==}
     engines: {node: '>=18'}
 
+  prexit@2.3.0:
+    resolution: {integrity: sha512-mX+LIbtS0anKtl2PykYabxninwloblUQMRO6CubeSmjxb+kKlATuJoH9UeN8NLE4TgIEFWfBXw7V3GkWbBrSmg==}
+    engines: {node: '>=12'}
+
   prismjs@1.27.0:
     resolution: {integrity: sha512-t13BGPUlFDR7wRB5kQDG4jjl7XeuH6jbJGt11JHPL96qwsEHNX2+68tFXqc1/k+/jALsbSWJKUOT/hcYAZ5LkA==}
     engines: {node: '>=6'}
@@ -5766,6 +5773,8 @@ snapshots:
     dependencies:
       parse-ms: 4.0.0
 
+  prexit@2.3.0: {}
+
   prismjs@1.27.0: {}
 
   prismjs@1.30.0: {}
diff --git a/src/server/service/claude-code/ClaudeCodeTaskController.ts b/src/server/service/claude-code/ClaudeCodeTaskController.ts
index 7bb066e..a6951c1 100644
--- a/src/server/service/claude-code/ClaudeCodeTaskController.ts
+++ b/src/server/service/claude-code/ClaudeCodeTaskController.ts
@@ -1,6 +1,7 @@
 import { execSync } from "node:child_process";
 import { query } from "@anthropic-ai/claude-code";
 import { ulid } from "ulid";
+import prexit from "prexit";
 import { type EventBus, getEventBus } from "../events/EventBus";
 import { createMessageGenerator } from "./createMessageGenerator";
 import type {
@@ -20,6 +21,12 @@ export class ClaudeCodeTaskController {
       .toString()
       .trim();
     this.eventBus = getEventBus();
+
+    prexit(() => {
+      this.aliveTasks.forEach((task) => {
+        task.abortController.abort();
+      });
+    });
   }
 
   public get aliveTasks() {