diff --git a/cecli/tui/app.py b/cecli/tui/app.py
index 464726a61c1..fc87bd7211b 100644
--- a/cecli/tui/app.py
+++ b/cecli/tui/app.py
@@ -2,6 +2,7 @@
 
 import concurrent.futures
 import json
+import platform
 import queue
 import time
 from functools import lru_cache
@@ -359,6 +360,11 @@ def on_mouse_up(self, event: events.MouseUp) -> None:
             self._mouse_hold_timer = None
         self.update_key_hints(generating=self._currently_generating)
 
+    def on_mouse_move(self, event: events.MouseMove) -> None:
+        """Handle mouse move events to prevent strange characters on Windows."""
+        if platform.system() == "Windows":
+            event.stop()
+
     def _show_select_hint(self) -> None:
         """Show the shift+drag to select hint."""
         try:
diff --git a/tests/tui/test_app.py b/tests/tui/test_app.py
new file mode 100644
index 00000000000..e6244d87cf2
--- /dev/null
+++ b/tests/tui/test_app.py
@@ -0,0 +1,37 @@
+from unittest.mock import MagicMock, patch
+
+import pytest
+from textual import events
+
+# Assuming TUI is in cecli.tui.app
+from cecli.tui.app import TUI
+
+
+@pytest.fixture
+def tui_instance(monkeypatch):
+    """A pytest fixture to create a mocked TUI instance."""
+    monkeypatch.setattr("cecli.tui.app.TUI.__init__", lambda *args, **kwargs: None)
+    tui = TUI(coder_worker=None, output_queue=None, input_queue=None, args=None)
+    tui._mouse_hold_timer = None
+    tui._currently_generating = False
+    return tui
+
+
+def test_on_mouse_move_windows(tui_instance):
+    """
+    Test that on_mouse_move stops the event on Windows.
+    """
+    with patch("platform.system", return_value="Windows"):
+        mock_event = MagicMock(spec=events.MouseMove)
+        tui_instance.on_mouse_move(mock_event)
+        mock_event.stop.assert_called_once()
+
+
+def test_on_mouse_move_linux(tui_instance):
+    """
+    Test that on_mouse_move does not stop the event on Linux.
+    """
+    with patch("platform.system", return_value="Linux"):
+        mock_event = MagicMock(spec=events.MouseMove)
+        tui_instance.on_mouse_move(mock_event)
+        mock_event.stop.assert_not_called()