diff --git a/vvp/Makefile.in b/vvp/Makefile.in
index 79f2c5c65..582893149 100644
--- a/vvp/Makefile.in
+++ b/vvp/Makefile.in
@@ -50,6 +50,7 @@ PS2PDF = @PS2PDF@
 
 CPPFLAGS = -I. -I.. -I $(srcdir) -I$(srcdir)/.. @CPPFLAGS@ @DEFS@
 CXXFLAGS = -Wall @CXXFLAGS@
+CFLAGS = -Wall @CFLAGS@
 LDFLAGS = @rdynamic@ @LDFLAGS@
 LIBS = @LIBS@ @EXTRALIBS@