1diff --git a/pppd/Makefile.linux b/pppd/Makefile.linux
2index 060db6a..c151c62 100644
3--- a/pppd/Makefile.linux
4+++ b/pppd/Makefile.linux
5@@ -117,7 +117,7 @@ CFLAGS += -DHAS_SHADOW
6 #LIBS += -lshadow $(LIBS)
7 endif
8
9-ifneq ($(wildcard /usr/include/crypt.h),)
10+ifneq ($(wildcard @glibc@/include/crypt.h),)
11 CFLAGS += -DHAVE_CRYPT_H=1
12 LIBS += -lcrypt
13 endif
14@@ -169,7 +169,7 @@ LIBS += -ldl
15 endif
16
17 ifdef FILTER
18-ifneq ($(wildcard /usr/include/pcap-bpf.h),)
19+ifneq ($(wildcard @libpcap@/include/pcap-bpf.h),)
20 LIBS += -lpcap
21 CFLAGS += -DPPP_FILTER
22 endif