diff -urNp a/net-snmp-config.in b/net-snmp-config.in
--- a/net-snmp-config.in	2018-07-18 13:43:12.264426052 +0200
+++ b/net-snmp-config.in	2018-07-18 13:52:06.917089518 +0200
@@ -140,10 +140,10 @@ else
       ;;
     #################################################### compile
     --base-cflags)
-      echo @CFLAGS@ @CPPFLAGS@ -I${NSC_INCLUDEDIR}
+      echo -I${NSC_INCLUDEDIR}
       ;;
     --cflags|--cf*)
-      echo @CFLAGS@ @DEVFLAGS@ @CPPFLAGS@ -I. -I${NSC_INCLUDEDIR}
+      echo @DEVFLAGS@ -I. -I${NSC_INCLUDEDIR}
       ;;
     --srcdir)
       echo $NSC_SRCDIR
diff -urNp a/perl/Makefile.PL b/perl/Makefile.PL
--- a/perl/Makefile.PL	2020-08-26 08:32:52.498909823 +0200
+++ b/perl/Makefile.PL	2020-08-26 09:30:45.584951552 +0200
@@ -1,3 +1,4 @@
+use lib '.';
 use strict;
 use warnings;
 use ExtUtils::MakeMaker;
diff -urNp a/perl/MakefileSubs.pm b/perl/MakefileSubs.pm
--- a/perl/MakefileSubs.pm	2020-08-26 08:32:52.498909823 +0200
+++ b/perl/MakefileSubs.pm	2020-08-26 08:36:44.097218448 +0200
@@ -116,7 +116,7 @@ sub AddCommonParams {
 	append($Params->{'CCFLAGS'}, $cflags);
 	append($Params->{'CCFLAGS'}, $Config{'ccflags'});
 	# Suppress known Perl header shortcomings.
-	$Params->{'CCFLAGS'} =~ s/ -W(cast-qual|write-strings)//g;
+	$Params->{'CCFLAGS'} =~ s/ -W(inline|strict-prototypes|write-strings|cast-qual|no-char-subscripts)//g;
 	append($Params->{'CCFLAGS'}, '-Wformat');
     }
 }