diff --git a/tutorials/rendering/viewports.rst b/tutorials/rendering/viewports.rst
index 4594252adace..19927a23ac96 100644
--- a/tutorials/rendering/viewports.rst
+++ b/tutorials/rendering/viewports.rst
@@ -181,7 +181,7 @@ it using (for example):
  .. code-tab:: csharp
 
     // Wait until the frame has finished before getting the texture.
-    RenderingServer.FramePostDraw += HandlePostDraw;
+    await RenderingServer.Singleton.ToSignal(RenderingServer.SignalName.FramePostDraw);
     // You can get the image after this.
 
 Viewport Container