diff --git a/mozilla/layout/generic/nsLineLayout.cpp b/mozilla/layout/generic/nsLineLayout.cpp
index d8f8e3da562..e7219c8f853 100644
--- a/mozilla/layout/generic/nsLineLayout.cpp
+++ b/mozilla/layout/generic/nsLineLayout.cpp
@@ -40,6 +40,7 @@
  * ***** END LICENSE BLOCK ***** */
 #include "nsCOMPtr.h"
 #include "nsLineLayout.h"
+#include "nsBlockFrame.h"
 #include "nsInlineFrame.h"
 #include "nsStyleConsts.h"
 #include "nsHTMLContainerFrame.h"
diff --git a/mozilla/layout/html/base/src/nsLineLayout.cpp b/mozilla/layout/html/base/src/nsLineLayout.cpp
index d8f8e3da562..e7219c8f853 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.cpp
+++ b/mozilla/layout/html/base/src/nsLineLayout.cpp
@@ -40,6 +40,7 @@
  * ***** END LICENSE BLOCK ***** */
 #include "nsCOMPtr.h"
 #include "nsLineLayout.h"
+#include "nsBlockFrame.h"
 #include "nsInlineFrame.h"
 #include "nsStyleConsts.h"
 #include "nsHTMLContainerFrame.h"