diff --git a/t/12_diff_opensslversions.t b/t/12_diff_opensslversions.t
new file mode 100755
index 0000000..e88d33b
--- /dev/null
+++ b/t/12_diff_opensslversions.t
@@ -0,0 +1,81 @@
+#!/usr/bin/env perl
+
+# Baseline diff test against testssl.sh (csv output)
+#
+# This runs a basic test with the supplied openssl vs /usr/bin/openssl
+
+use strict;
+use Test::More;
+use Data::Dumper;
+use Text::Diff;
+
+my $tests = 0;
+my $prg="./testssl.sh";
+my $check2run="--protocols --std --server-preference --fs --header --renegotiation --crime --breach --poodle --tls-fallback --sweet32 --beast --lucky13 --freak --logjam --drown --rc4 --phone-out --client-simulation -q --ip=one --color 0 --csvfile";
+my $csvfile="tmp.csv";
+my $csvfile2="tmp2.csv";
+my $cat_csvfile="";
+my $cat_csvfile2="";
+my $uri="google.com";
+my $diff="";
+my $distro_openssl="/usr/bin/openssl";
+my @args="";
+
+die "Unable to open $prg" unless -f $prg;
+die "Unable to open $distro_openssl" unless -f $distro_openssl;
+
+# Provide proper start conditions
+unlink "tmp.csv";
+unlink "tmp2.csv";
+
+#1 run
+printf "\n%s\n", "Diff test IPv4 with supplied openssl against \"$uri\"";
+@args="$prg $check2run $csvfile $uri 2>&1";
+system("@args") == 0
+     or die ("FAILED: \"@args\"");
+
+# 2
+printf "\n%s\n", "Diff test IPv4 with $distro_openssl against \"$uri\"";
+@args="$prg $check2run $csvfile2 --openssl=$distro_openssl $uri 2>&1";
+system("@args") == 0
+     or die ("FAILED: \"@args\" ");
+
+$cat_csvfile  = `cat $csvfile`;
+$cat_csvfile2 = `cat $csvfile2`;
+
+# Filter for changes that are allowed to occur
+$cat_csvfile  =~ s/HTTP_clock_skew.*\n//g;
+$cat_csvfile2 =~ s/HTTP_clock_skew.*\n//g;
+
+# HTTP time
+$cat_csvfile  =~ s/HTTP_headerTime.*\n//g;
+$cat_csvfile2 =~ s/HTTP_headerTime.*\n//g;
+
+#engine_problem
+$cat_csvfile  =~  s/"engine_problem.*\n//g;
+$cat_csvfile2  =~ s/"engine_problem.*\n//g;
+
+# PR #2628. TL:DR; make the kx between tls_sockets() and openssl the same for this CI run
+$cat_csvfile  =~  s/ECDH 256/ECDH 253/g;
+$cat_csvfile  =~  s/ECDH\/MLKEM/ECDH 253  /g;
+
+# Nonce in CSP
+$cat_csvfile  =~ s/.nonce-.* //g;
+$cat_csvfile2 =~ s/.nonce-.* //g;
+
+$diff = diff \$cat_csvfile, \$cat_csvfile2;
+
+# Compare the differences -- and print them if there were any
+ok( $cat_csvfile eq $cat_csvfile2, "Check whether CSV outputs match" ) or
+     diag ("\n%s\n", "$diff");
+
+unlink "tmp.csv";
+unlink "tmp2.csv";
+
+$tests++;
+done_testing($tests);
+printf "\n";
+
+
+#  vim:ts=5:sw=5:expandtab
+