diff --git a/panda/src/display/graphicsBuffer.cxx b/panda/src/display/graphicsBuffer.cxx
index 1fd967a9ce..3e63d02aee 100644
--- a/panda/src/display/graphicsBuffer.cxx
+++ b/panda/src/display/graphicsBuffer.cxx
@@ -49,6 +49,7 @@ GraphicsBuffer(GraphicsPipe *pipe, GraphicsStateGuardian *gsg,
   _x_size = x_size;
   _y_size = y_size;
   _has_size = true;
+  _default_display_region->compute_pixels(_x_size, _y_size);
   _open_request = OR_none;
 }