diff --git a/Multi-Viewports.md b/Multi-Viewports.md
index 97df128..4aa30da 100644
--- a/Multi-Viewports.md
+++ b/Multi-Viewports.md
@@ -33,11 +33,14 @@ if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
 {
     ImGui::UpdatePlatformWindows();
     ImGui::RenderPlatformWindowsDefault();
+    // TODO for OpenGL: restore current GL context.
 }
 ```
 
 That's pretty much it.
-There are a few additional multi-viewports related configuration flags in the io structure which you may toy with.
+There may be additional calls required surrounding this depending on the backend you are using: OpenGL in particular needs backup/restore of current GL context. Check the [example project](https://github.com/ocornut/imgui/tree/docking/examples) appropriate to your setup for details.
+
+There are a few additional multi-viewports related configuration flags in the IO structure which you may toy with.
 
 If you are using a custom back-end, refer to the `ImGuiPlatformIO` structure and existing `backends/` + `examples/` to implement support for multi-viewports in your engine. This is not particularly easy to add.