--- a/Makefile	Tue Dec 13 22:28:44 2005 +0000
+++ b/Makefile	Wed Dec 14 06:16:34 2005 +0000
@@ -293,7 +293,7 @@
 # GNU make can only test for (in)equality
 # this is a workaround to test for >=
 ifeq ($(shell expr $(CC_VERSION) \>= 29), 1)
-  CFLAGS += -O -Wall -Wno-multichar -Wsign-compare -Wstrict-prototypes
+  CFLAGS += -O -Wall -Wno-multichar -Wsign-compare -Wstrict-prototypes -Wundef
   CFLAGS += -Wwrite-strings -Wpointer-arith
 endif
 ifeq ($(shell expr $(CC_VERSION) \>= 30), 1)