diff --git a/package.json b/package.json
index c15471e5..184d5c9a 100644
--- a/package.json
+++ b/package.json
@@ -12,9 +12,10 @@
     "vite-preview": "vite preview",
     "tauri": "tauri",
     "tauri-dev": "tauri dev",
+    "task-kill": "python task_kill.py",
     "clean": "python clean.py",
-    "dev": "npm run build-python && npm run dev-ui",
-    "dev-cuda": "npm run build-python-cuda && npm run dev-ui",
+    "dev": "npm run task-kill && npm run build-python && npm run dev-ui",
+    "dev-cuda": "npm run task-kill && npm run build-python-cuda && npm run dev-ui",
     "dev-ui": "npm-run-all --parallel vite tauri-dev",
     "build": "npm run clean && npm run build-python && npm run vite-build && npm run tauri build",
     "build-cuda": "npm run clean && npm run build-python-cuda && npm run vite-build && npm run tauri build",
diff --git a/task_kill.py b/task_kill.py
new file mode 100644
index 00000000..ee869511
--- /dev/null
+++ b/task_kill.py
@@ -0,0 +1,12 @@
+import subprocess
+
+# VRCT-sidecar.exe を強制終了
+try:
+    subprocess.run(
+        ["taskkill", "/IM", "VRCT-sidecar.exe", "/F"],
+        check=False,
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL
+    )
+except Exception:
+    pass
\ No newline at end of file