diff -Naur ppp-2.4.4.orig/pppd/Makefile.linux ppp-2.4.4/pppd/Makefile.linux
--- ppp-2.4.4.orig/pppd/Makefile.linux	2009-05-07 22:25:24.000000000 -0400
+++ ppp-2.4.4/pppd/Makefile.linux	2009-05-07 22:28:44.000000000 -0400
@@ -170,8 +170,8 @@
 
 ifdef FILTER
 ifneq ($(wildcard /usr/include/pcap-bpf.h),)
-LIBS    += -lpcap
-CFLAGS  += -DPPP_FILTER
+LIBS    += -lpcap -L$(STAGING_DIR)/usr/lib
+CFLAGS  += -DPPP_FILTER -I$(STAGING_DIR)/usr/include
 endif
 endif