diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index a85cd12374..5eb29b3e3e 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1651,10 +1651,15 @@ if iswindows:
                 msg = ctypes.wintypes.MSG.from_address(message.__int__())
                 # https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-settingchange
                 if msg.message == 0x001A and msg.lParam:  # WM_SETTINGCHANGE
-                    if ctypes.wstring_at(msg.lParam) == 'ImmersiveColorSet':
-                        QApplication.instance().check_for_windows_palette_change()
-                        # prevent Qt from handling this event
-                        return True, 0
+                    try:
+                        s = ctypes.wstring_at(msg.lParam)
+                    except OSError:
+                        pass
+                    else:
+                        if s == 'ImmersiveColorSet':
+                            QApplication.instance().check_for_windows_palette_change()
+                            # prevent Qt from handling this event
+                            return True, 0
             return False, 0