diff --git a/pyproject.toml b/pyproject.toml
index 669a3a46..1e597d1b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,7 +39,7 @@ packages = [{include = "src"}]
 
 [tool.poetry.dependencies]
 python = "^3.11"
-python-telegram-bot = {version = "^22.6", extras = ["rate-limiter"]}
+python-telegram-bot = {version = "^22.6", extras = ["rate-limiter", "webhooks"]}
 structlog = "^25.4.0"
 pydantic = "^2.11.5"
 pydantic-settings = "^2.9.1"
diff --git a/src/bot/core.py b/src/bot/core.py
index 2d5e99bb..13e5df80 100644
--- a/src/bot/core.py
+++ b/src/bot/core.py
@@ -212,8 +212,10 @@ async def start(self) -> None:
             self.is_running = True
 
             if self.settings.webhook_url:
-                # Webhook mode
-                await self.app.run_webhook(
+                # Webhook mode - use start/start_webhook instead of run_webhook
+                # to avoid "Cannot close a running event loop" in async context
+                await self.app.start()
+                await self.app.updater.start_webhook(
                     listen="0.0.0.0",
                     port=self.settings.webhook_port,
                     url_path=self.settings.webhook_path,
@@ -221,6 +223,10 @@ async def start(self) -> None:
                     drop_pending_updates=True,
                     allowed_updates=Update.ALL_TYPES,
                 )
+
+                # Keep running until manually stopped
+                while self.is_running:
+                    await asyncio.sleep(1)
             else:
                 # Polling mode - initialize and start polling manually
                 await self.app.initialize()
diff --git a/tests/unit/test_bot/test_webhook_start.py b/tests/unit/test_bot/test_webhook_start.py
new file mode 100644
index 00000000..6dba8135
--- /dev/null
+++ b/tests/unit/test_bot/test_webhook_start.py
@@ -0,0 +1,100 @@
+"""Tests for webhook startup mode — verifies start_webhook is used instead of run_webhook."""
+
+import asyncio
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+import src.bot.core as core_module
+from src.bot.core import ClaudeCodeBot
+from src.config import create_test_config
+
+
+@pytest.fixture
+def bot_ready(monkeypatch):
+    """Create a bot with mocked Application, already initialized."""
+    settings = create_test_config()
+    deps = {"storage": MagicMock(), "security": MagicMock()}
+    bot = ClaudeCodeBot(settings, deps)
+
+    builder = MagicMock()
+    builder.token.return_value = builder
+    builder.rate_limiter.return_value = builder
+    builder.connect_timeout.return_value = builder
+    builder.read_timeout.return_value = builder
+    builder.write_timeout.return_value = builder
+    builder.pool_timeout.return_value = builder
+
+    app = MagicMock()
+    app.bot = MagicMock()
+    app.bot.set_my_commands = AsyncMock()
+    app.initialize = AsyncMock()
+    app.start = AsyncMock()
+    app.add_handler = MagicMock()
+    app.add_error_handler = MagicMock()
+    builder.build.return_value = app
+
+    monkeypatch.setattr(
+        core_module.Application, "builder", MagicMock(return_value=builder)
+    )
+    monkeypatch.setattr(
+        core_module, "FeatureRegistry", MagicMock(return_value=MagicMock())
+    )
+    monkeypatch.setattr(bot, "_set_bot_commands", AsyncMock())
+    monkeypatch.setattr(bot, "_register_handlers", MagicMock())
+    monkeypatch.setattr(bot, "_add_middleware", MagicMock())
+
+    return bot, app
+
+
+@pytest.mark.asyncio
+async def test_webhook_mode_uses_start_webhook_not_run_webhook(bot_ready):
+    """In webhook mode, start_webhook must be called instead of run_webhook.
+
+    run_webhook manages its own event loop and raises
+    'Cannot close a running event loop' when called inside asyncio.run().
+    """
+    bot, app = bot_ready
+    bot.settings.webhook_url = "https://example.com:8443/webhook"
+
+    # Make run_webhook raise if it's ever called (regression guard)
+    app.run_webhook = AsyncMock(
+        side_effect=RuntimeError("Cannot close a running event loop")
+    )
+    app.updater.start_webhook = AsyncMock()
+
+    # Stop the while loop after one tick
+    async def wake_after_start():
+        await asyncio.sleep(0.05)
+        bot.is_running = False
+
+    asyncio.create_task(wake_after_start())
+
+    await bot.start()
+
+    app.run_webhook.assert_not_called()
+    app.updater.start_webhook.assert_awaited_once()
+    call_kwargs = app.updater.start_webhook.call_args.kwargs
+    assert call_kwargs["listen"] == "0.0.0.0"
+    assert call_kwargs["port"] == 8443
+    assert call_kwargs["url_path"] == "/webhook"
+    assert call_kwargs["webhook_url"] == "https://example.com:8443/webhook"
+
+
+@pytest.mark.asyncio
+async def test_polling_mode_uses_start_polling(bot_ready):
+    """Polling mode should use start_polling, unchanged by the webhook fix."""
+    bot, app = bot_ready
+    app.updater.start_polling = AsyncMock()
+
+    async def wake_after_start():
+        await asyncio.sleep(0.05)
+        bot.is_running = False
+
+    asyncio.create_task(wake_after_start())
+
+    await bot.start()
+
+    app.updater.start_polling.assert_awaited_once()
+    app.updater.start_webhook.assert_not_called()
+    app.run_webhook.assert_not_called()