diff --git a/WinPowerDMS/WinPowerDMS.c b/WinPowerDMS/WinPowerDMS.c
index abb2d36..f493d9a 100644
--- a/WinPowerDMS/WinPowerDMS.c
+++ b/WinPowerDMS/WinPowerDMS.c
@@ -337,7 +337,7 @@ static LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM l
     return DefWindowProc(hWnd, uMsg, wParam, lParam);
 }
 
-int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
+int WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR lpCmdLine, _In_ int nShowCmd) {
     if (!LoadPrefs()) { // set both battery and AC to current display mode if there are no preferences set
         DISPLAY_MODE currentMode = GetCurrentDisplayMode();
         userPrefs.modeAC = currentMode;