diff --git a/mozilla/content/shared/public/makefile.win b/mozilla/content/shared/public/makefile.win
index 903a5905883..b02b57aaa7e 100644
--- a/mozilla/content/shared/public/makefile.win
+++ b/mozilla/content/shared/public/makefile.win
@@ -54,5 +54,5 @@ EXPORTS =				\
 include <$(DEPTH)\config\rules.mak>
 
 !ifdef IBMBIDI
-  EXPORTS += nsBidiUtils.h
+  EXPORTS = $(EXPORTS) nsBidiUtils.h
 !endif