--- a/configure.ac.orig	2019-05-25 02:28:49.000000000 +0800
+++ b/configure.ac	2020-01-17 12:31:31.598907767 +0800
@@ -230,18 +230,19 @@
 dnl Check IPv6 raw sending flavor.
 CHECK_IPV6_IPPROTO_RAW
 
-m4_define_default([_AM_PYTHON_INTERPRETER_LIST],[python2 python2.7 python2.6 python2.5 python2.4 python])
-AM_PATH_PYTHON([2.4], [HAVE_PYTHON=true], [HAVE_PYTHON=false])
+m4_define_default([_AM_PYTHON_INTERPRETER_LIST],[python3 python3.8 python3.7 python3.6 python3.5 python])
+AM_PATH_PYTHON([3.5], [HAVE_PYTHON=true], [HAVE_PYTHON=false])
 HAVE_PYTHON2=false
-if test $HAVE_PYTHON && test "x${PYTHON_VERSION%%.*}" = "x2"; then
-    HAVE_PYTHON2=true
+HAVE_PYTHON3=false
+if test $HAVE_PYTHON && test "x${PYTHON_VERSION%%.*}" = "x3"; then
+    HAVE_PYTHON3=true
 fi
 
 NDIFFDIR=ndiff
 
 # Do they want Ndiff?
 AC_ARG_WITH(ndiff, AC_HELP_STRING([--without-ndiff], [Skip installation of the Ndiff utility]), [], [with_ndiff=check])
-if $HAVE_PYTHON2 ; then : ;
+if $HAVE_PYTHON3 ; then : ;
 else
   if test "$with_ndiff" = "check" ; then
     AC_MSG_WARN([Not building Ndiff because Python 2.x with x>=4 was not found])