--- a/Makefile.defs.in
+++ b/Makefile.defs.in
@@ -24,6 +24,7 @@ LDFLAGS += @LIBS@
CPPFLAGS += @CPPFLAGS@
+CFLAGS :=
CFLAGS += @CFLAGS@ @DEFS@
CFLAGS += -DDEFAULT_INCLUDE_PATH="\"$(confdir)\""
CFLAGS += -include config.h