--- a/configure.ac	2018-07-20 16:15:42.284633906 +0200
+++ b/configure.ac	2018-07-20 16:16:09.812296939 +0200
@@ -162,16 +162,8 @@
      ;;
   *)
      AC_MSG_RESULT($withval)
-     if test -f $withval/pcap.h -a \
-         -f $withval/libpcap.a -a \
-         -d $withval/pcap; then
-        owd=`pwd`
-        if cd $withval; then withval=`pwd`; cd $owd; fi
         PCAPINC="-I$withval -I$withval/bpf"
         PCAPLIB="-L$withval -lpcap"
-     else
-        AC_ERROR(pcap.h, net/bpf.h, or libpcap.a not found in $withval)
-     fi
      ;;
   esac ],
 [ if test -f ${prefix}/include/pcap.h; then