diff --git a/gateway/run.py b/gateway/run.py
index 559adae89bf06..e6c536dc866a9 100644
--- a/gateway/run.py
+++ b/gateway/run.py
@@ -8116,14 +8116,19 @@ async def _handle_reset_command(self, event: MessageEvent) -> Union[str, Ephemer
         # previous conversation must not survive the reset.
         self._clear_session_boundary_security_state(session_key)
 
-        # Fire plugin on_session_finalize hook (session boundary)
-        try:
-            from hermes_cli.plugins import invoke_hook as _invoke_hook
-            _old_sid = old_entry.session_id if old_entry else None
-            _invoke_hook("on_session_finalize", session_id=_old_sid,
-                         platform=source.platform.value if source.platform else "")
-        except Exception:
-            pass
+        # Fire plugin on_session_finalize hook only when a prior session
+        # actually existed. On a first-message /new there is nothing to
+        # finalize, and emitting session_id=None creates a fake boundary event.
+        if old_entry is not None:
+            try:
+                from hermes_cli.plugins import invoke_hook as _invoke_hook
+                _invoke_hook(
+                    "on_session_finalize",
+                    session_id=old_entry.session_id,
+                    platform=source.platform.value if source.platform else "",
+                )
+            except Exception:
+                pass
 
         # Emit session:end hook (session is ending)
         await self.hooks.emit("session:end", {
diff --git a/tests/gateway/test_session_boundary_hooks.py b/tests/gateway/test_session_boundary_hooks.py
index 255795492fc70..ee73c93b782e6 100644
--- a/tests/gateway/test_session_boundary_hooks.py
+++ b/tests/gateway/test_session_boundary_hooks.py
@@ -99,6 +99,30 @@ async def test_reset_fires_reset_hook(mock_invoke_hook):
     )
 
 
+@pytest.mark.asyncio
+@patch("hermes_cli.plugins.invoke_hook")
+async def test_reset_without_existing_session_skips_finalize_hook(mock_invoke_hook):
+    """First-session /new should not emit a fake finalize event with None."""
+    runner = _make_runner()
+    session_key = build_session_key(_make_source())
+    runner.session_store._entries = {}
+    runner.session_store.reset_session.return_value = None
+
+    await runner._handle_reset_command(_make_event("/new"))
+
+    finalize_calls = [
+        call for call in mock_invoke_hook.call_args_list if call[0][0] == "on_session_finalize"
+    ]
+    assert finalize_calls == []
+    runner.session_store.reset_session.assert_called_once_with(session_key)
+    runner.session_store.get_or_create_session.assert_called_once_with(
+        _make_source(), force_new=True
+    )
+    mock_invoke_hook.assert_any_call(
+        "on_session_reset", session_id="sess-new", platform="telegram"
+    )
+
+
 @pytest.mark.asyncio
 @patch("hermes_cli.plugins.invoke_hook")
 async def test_finalize_before_reset(mock_invoke_hook):