--- a/layout/generic/nsRubyTextContainerFrame.cpp
+++ b/layout/generic/nsRubyTextContainerFrame.cpp
@@ -5,16 +5,17 @@
  * http://mozilla.org/MPL/2.0/. */
 
 /* rendering object for CSS "display: ruby-text-container" */
 
 #include "nsRubyTextContainerFrame.h"
 
 #include "mozilla/UniquePtr.h"
 #include "mozilla/WritingModes.h"
+#include "nsLineLayout.h"
 #include "nsPresContext.h"
 #include "nsStyleContext.h"
 
 using namespace mozilla;
 
 //----------------------------------------------------------------------
 
 // Frame class boilerplate