diff --git a/layout/generic/nsPageFrame.cpp b/layout/generic/nsPageFrame.cpp
index b801d86ac761..20cdd2aa6525 100644
--- a/layout/generic/nsPageFrame.cpp
+++ b/layout/generic/nsPageFrame.cpp
@@ -16,6 +16,7 @@
  * Reserved.
  */
 #include "nsPageFrame.h"
+#include "nsHTMLParts.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
 #include "nsIStyleContext.h"
diff --git a/layout/html/base/src/nsPageFrame.cpp b/layout/html/base/src/nsPageFrame.cpp
index b801d86ac761..20cdd2aa6525 100644
--- a/layout/html/base/src/nsPageFrame.cpp
+++ b/layout/html/base/src/nsPageFrame.cpp
@@ -16,6 +16,7 @@
  * Reserved.
  */
 #include "nsPageFrame.h"
+#include "nsHTMLParts.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
 #include "nsIStyleContext.h"