diff --git a/distrib/msw/tmake/vc.t b/distrib/msw/tmake/vc.t
index 32c9b3dd20..e157c70522 100644
--- a/distrib/msw/tmake/vc.t
+++ b/distrib/msw/tmake/vc.t
@@ -104,7 +104,7 @@ $(CPPFLAGS) /Fo$@ /c /Tp $<
 
 {..\common}.c{..\common\$D}.obj:
 	cl @<<
-$(CPPFLAGS) /Fo$@ /c /Tc $<
+$(CPPFLAGS2) /Fo$@ /c /Tc $<
 <<
 
 {..\msw}.cpp{..\msw\$D}.obj:
diff --git a/src/msw/makefile.vc b/src/msw/makefile.vc
index bc68a1b2ef..2e1c14e2a4 100644
--- a/src/msw/makefile.vc
+++ b/src/msw/makefile.vc
@@ -60,7 +60,7 @@ $(CPPFLAGS) /Fo$@ /c /Tp $<
 
 {..\common}.c{..\common\$D}.obj:
 	cl @<<
-$(CPPFLAGS) /Fo$@ /c /Tc $<
+$(CPPFLAGS2) /Fo$@ /c /Tc $<
 <<
 
 {..\msw}.cpp{..\msw\$D}.obj: