diff --git a/layout/mathml/nsMathMLmactionFrame.cpp b/layout/mathml/nsMathMLmactionFrame.cpp
index eb0069fdcfa2..d4b383d15727 100644
--- a/layout/mathml/nsMathMLmactionFrame.cpp
+++ b/layout/mathml/nsMathMLmactionFrame.cpp
@@ -217,6 +217,7 @@ nsMathMLmactionFrame::GetSelectedFrame()
 
   mChildCount = count;
   mSelection = selection;
+  TransmitAutomaticData();
 
   return mSelectedFrame;
 }