diff --git a/mozilla/xpcom/typelib/xpt/tools/makefile.win b/mozilla/xpcom/typelib/xpt/tools/makefile.win
index cb98385d409..4fad270ff50 100644
--- a/mozilla/xpcom/typelib/xpt/tools/makefile.win
+++ b/mozilla/xpcom/typelib/xpt/tools/makefile.win
@@ -36,6 +36,8 @@ LLIBS=                      \
  $(DIST)\lib\xpcomxpt_s.lib \
  $(NULL)
 
+MOZ_NO_COVERAGE=1
+
 include <$(DEPTH)\config\rules.mak>
 
 # build these xpt tools early so that it'll be