diff --git a/widget/public/Makefile.in b/widget/public/Makefile.in
index ea3a679cebd..0d5a819b6a9 100644
--- a/widget/public/Makefile.in
+++ b/widget/public/Makefile.in
@@ -75,6 +75,7 @@ EXPORTS = \
 	nsIFontSizeIterator.h \
 	nsIFontRetrieverService.h \
 	nsIContextMenu.h \
+	nsIXlibWindowService.h \
 	$(NULL)
 
 EXPORTS := $(addprefix $(srcdir)/, $(EXPORTS))