diff --git a/CLAUDE.md b/CLAUDE.md
index 47dc3e3..c317064 120000
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -1 +1 @@
-AGENTS.md
\ No newline at end of file
+AGENTS.md
diff --git a/deploy/command/update.py b/deploy/command/update.py
index 896d8aa..ce3a0ef 100644
--- a/deploy/command/update.py
+++ b/deploy/command/update.py
@@ -44,6 +44,13 @@
     default=None,
     help="Subdirectory within the repo to use as the service root (for monorepos).",
 )
+@click.option(
+    "--watch",
+    "watch",
+    is_flag=True,
+    default=False,
+    help="Stream service logs with journalctl after a successful update.",
+)
 @click.pass_context
 def update(  # noqa: C901
     ctx: click.Context,
@@ -54,6 +61,7 @@ def update(  # noqa: C901
     ssh_port: int | None,
     ignore_hooks: bool,
     repo_subdir: str | None,
+    watch: bool,
 ) -> None:
     """Update an existing deployment instance."""
     cfg = load_config(ctx.obj["config"], instance_name)
@@ -189,3 +197,10 @@ def run_hooks(hook_name: str) -> bool:
     run_hooks("post-update-success")
 
     click.secho(f"\nInstance {instance_name!r} updated successfully.", fg="green")
+
+    if watch:
+        click.secho("\nWatching service logs (Ctrl+C to stop)…", fg="cyan")
+        try:
+            executor.stream(f"journalctl --user -u {instance_name} -f")
+        except KeyboardInterrupt:
+            click.echo()
diff --git a/deploy/utils/executor.py b/deploy/utils/executor.py
index 618bfbd..f93e18b 100644
--- a/deploy/utils/executor.py
+++ b/deploy/utils/executor.py
@@ -108,6 +108,19 @@ def capture(self, command: str, cwd: str | None = None) -> str:
 
         return result.stdout.strip()
 
+    def stream(self, command: str, cwd: str | None = None) -> None:
+        """Run a long-lived streaming command (e.g. journalctl -f).
+
+        Output goes directly to the terminal. Returns when the process exits
+        or is interrupted (Ctrl+C).
+        """
+        argv = self._build_argv(command, cwd)
+        is_remote = isinstance(argv, list)
+        if self.verbose:
+            display = argv[-1] if is_remote else command
+            click.echo(f"$ {display}", err=True)
+        subprocess.run(argv, shell=not is_remote, cwd=cwd if not is_remote else None)  # noqa: S603
+
     def write_file(self, content: str, remote_path: str) -> None:
         """Write *content* to *remote_path* on the target host.
 
diff --git a/tests/test_update_watch.py b/tests/test_update_watch.py
new file mode 100644
index 0000000..3bbb85b
--- /dev/null
+++ b/tests/test_update_watch.py
@@ -0,0 +1,67 @@
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+import pytest
+from click.testing import CliRunner
+
+from deploy.command.update import update
+
+
+@pytest.fixture
+def runner():
+    return CliRunner()
+
+
+def _executor_mock():
+    mock = MagicMock()
+    mock.capture.return_value = "/home/deploy"
+    return mock
+
+
+def _invoke(runner, extra_args: list[str]):
+    with (
+        patch("deploy.command.update.Executor") as MockExecutor,
+        patch("deploy.command.update.load_config", return_value={}),
+    ):
+        mock_exec = _executor_mock()
+        MockExecutor.return_value = mock_exec
+        result = runner.invoke(
+            update,
+            ["service-myapp-production", "--type", "service", *extra_args],
+            obj={"config": "", "verbose": False},
+        )
+        return result, mock_exec
+
+
+def test_watch_streams_journalctl_after_success(runner):
+    result, mock_exec = _invoke(runner, ["--watch"])
+
+    assert result.exit_code == 0
+    mock_exec.stream.assert_called_once_with("journalctl --user -u service-myapp-production -f")
+
+
+def test_no_watch_does_not_stream(runner):
+    result, mock_exec = _invoke(runner, [])
+
+    assert result.exit_code == 0
+    mock_exec.stream.assert_not_called()
+
+
+def test_watch_handles_keyboard_interrupt(runner):
+    with (
+        patch("deploy.command.update.Executor") as MockExecutor,
+        patch("deploy.command.update.load_config", return_value={}),
+    ):
+        mock_exec = _executor_mock()
+        mock_exec.stream.side_effect = KeyboardInterrupt
+        MockExecutor.return_value = mock_exec
+
+        result = runner.invoke(
+            update,
+            ["service-myapp-production", "--type", "service", "--watch"],
+            obj={"config": "", "verbose": False},
+        )
+
+        assert result.exit_code == 0
+        mock_exec.stream.assert_called_once()