diff --git a/docs/README-windows.md b/docs/README-windows.md
index cd29c1f92..1e6d59c44 100644
--- a/docs/README-windows.md
+++ b/docs/README-windows.md
@@ -56,3 +56,11 @@ it change the value of `SDL_VIDEO_VULKAN` to 0 in `SDL_config_windows.h`. You
 must install the [Vulkan SDK](https://www.lunarg.com/vulkan-sdk/) in order to
 use Vulkan graphics in your application.
 
+## Transparent Window Support
+
+SDL uses the Desktop Window Manager (DWM) to create transparent windows. DWM is
+always enabled from Windows 8 and above. Windows 7 only enables DWM with Aero Glass
+theme.
+
+However, it cannot be guaranteed to work on all hardware configurations (an example
+is hybrid GPU systems, such as NVIDIA Optimus laptops).