add DPI_AWARENESS_CONTEXT_UNAWARE_GDISCALED define
diff --git a/src/video/windows/SDL_windowsvideo.h b/src/video/windows/SDL_windowsvideo.h
index 1a42b80..74c6207 100644
--- a/src/video/windows/SDL_windowsvideo.h
+++ b/src/video/windows/SDL_windowsvideo.h
@@ -115,11 +115,14 @@ DECLARE_HANDLE(DPI_AWARENESS_CONTEXT);
/* Windows 10 Creators Update */
#if NTDDI_VERSION < 0x0A000003
-
#define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((DPI_AWARENESS_CONTEXT)-4)
-
#endif /* NTDDI_VERSION < 0x0A000003 */
+/* Windows 10 version 1809 */
+#if NTDDI_VERSION < 0x0A000006
+#define DPI_AWARENESS_CONTEXT_UNAWARE_GDISCALED ((DPI_AWARENESS_CONTEXT)-5)
+#endif /* NTDDI_VERSION < 0x0A000006 */
+
typedef BOOL (*PFNSHFullScreen)(HWND, DWORD);
typedef void (*PFCoordTransform)(SDL_Window*, POINT*);