diff --git a/dom/base/nsFocusManager.cpp b/dom/base/nsFocusManager.cpp
index 596cb1178e7f..76c9a026b130 100644
--- a/dom/base/nsFocusManager.cpp
+++ b/dom/base/nsFocusManager.cpp
@@ -13,6 +13,7 @@
 #include "nsGkAtoms.h"
 #include "nsGlobalWindow.h"
 #include "nsContentUtils.h"
+#include "nsIContentParent.h"
 #include "nsIDocument.h"
 #include "nsIEditor.h"
 #include "nsPIDOMWindow.h"