diff --git a/server/src/ledgrab/utils/win_shutdown.py b/server/src/ledgrab/utils/win_shutdown.py
index 75def70..34e1906 100644
--- a/server/src/ledgrab/utils/win_shutdown.py
+++ b/server/src/ledgrab/utils/win_shutdown.py
@@ -101,16 +101,15 @@ class _WNDCLASS(ctypes.Structure):
     ]
 
 
-class _MSG(ctypes.Structure):
-    _fields_ = [
-        ("hwnd", wintypes.HWND),
-        ("message", wintypes.UINT),
-        ("wParam", wintypes.WPARAM),
-        ("lParam", wintypes.LPARAM),
-        ("time", wintypes.DWORD),
-        ("pt_x", wintypes.LONG),
-        ("pt_y", wintypes.LONG),
-    ]
+# Use the stdlib wintypes.MSG (rather than a project-local _MSG) so the
+# POINTER(MSG) type is shared with any other module that binds
+# user32.GetMessageW.argtypes — argtypes is a global on the cached DLL
+# handle, and two modules binding it with different POINTER classes for
+# the same C function fight each other (last writer wins, the other one's
+# byref() then trips Python 3.13's strict argtype check). PlatformDetector's
+# display-power monitor binds with POINTER(wintypes.MSG); aligning here
+# means whichever loads last produces the same binding.
+_MSG = wintypes.MSG
 
 
 def _bind_winapi() -> None: