diff --git a/panda/src/display/graphicsPipe.h b/panda/src/display/graphicsPipe.h
index 36f9a1cc26..df21ffc7fe 100644
--- a/panda/src/display/graphicsPipe.h
+++ b/panda/src/display/graphicsPipe.h
@@ -28,6 +28,7 @@
 
 class HardwareChannel;
 class GraphicsOutput;
+class GraphicsWindow;
 class GraphicsStateGuardian;
 class FrameBufferProperties;