diff --git a/src/bub/channels/runner.py b/src/bub/channels/runner.py
index 9b8a810..45c50f7 100644
--- a/src/bub/channels/runner.py
+++ b/src/bub/channels/runner.py
@@ -48,7 +48,6 @@ async def process_message(self, channel: BaseChannel, message: Any) -> None:
             self._last_mentioned_at = None
             logger.info("session.receive ignored session_id={} message={}", self.session_id, prompt)
             return
-        self._prompts.append(prompt)
         if prompt.startswith(","):
             logger.info("session.receive.command session_id={} message={}", self.session_id, prompt)
             try:
@@ -56,7 +55,9 @@ async def process_message(self, channel: BaseChannel, message: Any) -> None:
                 await channel.process_output(self.session_id, result)
             except Exception:
                 logger.exception("session.run.error session_id={}", self.session_id)
-        elif is_mentioned:
+            return
+        self._prompts.append(prompt)
+        if is_mentioned:
             # wait at most 1 second to reply to mentioned messages.
             self._last_mentioned_at = now
             logger.info("session.receive.mentioned session_id={} message={}", self.session_id, prompt)
diff --git a/tests/test_session_runner.py b/tests/test_session_runner.py
new file mode 100644
index 0000000..c166646
--- /dev/null
+++ b/tests/test_session_runner.py
@@ -0,0 +1,38 @@
+import pytest
+
+from bub.channels.runner import SessionRunner
+
+
+class DummyChannel:
+    output_channel = "dummy"
+
+    def __init__(self) -> None:
+        self.prompts: list[str] = []
+        self.outputs: list[tuple[str, object]] = []
+
+    def is_mentioned(self, _message: object) -> bool:
+        return True
+
+    async def get_session_prompt(self, message: object) -> tuple[str, str]:
+        assert isinstance(message, str)
+        return "session", message
+
+    async def run_prompt(self, session_id: str, prompt: str) -> str:
+        self.prompts.append(prompt)
+        return f"result:{session_id}"
+
+    async def process_output(self, session_id: str, output: object) -> None:
+        self.outputs.append((session_id, output))
+
+
+@pytest.mark.asyncio
+async def test_command_prompt_is_not_buffered() -> None:
+    channel = DummyChannel()
+    runner = SessionRunner("session", debounce_seconds=1, message_delay_seconds=1, active_time_window_seconds=60)
+
+    await runner.process_message(channel, ",help")
+
+    assert channel.prompts == [",help"]
+    assert channel.outputs == [("session", "result:session")]
+    assert runner._prompts == []
+    assert runner._running_task is None