diff --git a/editor/libeditor/text/nsTextEditRules.cpp b/editor/libeditor/text/nsTextEditRules.cpp
index ee28930efef4..51f89b0544e5 100644
--- a/editor/libeditor/text/nsTextEditRules.cpp
+++ b/editor/libeditor/text/nsTextEditRules.cpp
@@ -58,6 +58,7 @@
 #include "nsEditorUtils.h"
 #include "EditTxn.h"
 #include "nsIPref.h"
+#include "nsISupportsArray.h"
 
 // for IBMBIDI
 #include "nsIPresShell.h"