diff --git a/mozilla/docshell/base/nsIDocShell.idl b/mozilla/docshell/base/nsIDocShell.idl
index 81d16a42765..4d7b0496997 100644
--- a/mozilla/docshell/base/nsIDocShell.idl
+++ b/mozilla/docshell/base/nsIDocShell.idl
@@ -25,6 +25,10 @@
 #include "domstubs.idl"
 #include "nsIPref.idl"
 
+%{ C++
+#include "nsIPresContext.h"
+%}
+
 /**
  * The nsIDocShell
  */