diff --git a/Overlay.c b/Overlay.c
index 631147d..f4a9128 100644
--- a/Overlay.c
+++ b/Overlay.c
@@ -179,6 +179,9 @@ OverlayWndProc(HWND hWnd,
 
 		EndPaint(hWnd, &ps);
 		break;
+	case WM_ERASEBKGND:
+		// Do nothing
+		return 1;
 	case WM_MOUSEMOVE:
 		if (isDrag && (wParam & MK_LBUTTON)) {
 			POINTS ptPrev = ptCur;