diff --git a/mariadb-mtr.patch b/mariadb-mtr.patch
new file mode 100644
index 0000000..592f73c
--- /dev/null
+++ b/mariadb-mtr.patch
@@ -0,0 +1,70 @@
+diff --git a/mysql-test/mariadb-test-run.pl b/mysql-test/mariadb-test-run.pl
+index 594e052a16e..6a274b2d597 100755
+--- a/mysql-test/mariadb-test-run.pl
++++ b/mysql-test/mariadb-test-run.pl
+@@ -1491,7 +1491,6 @@ sub command_line_setup {
+       mtr_warning ("Port base $opt_port_base rounded down to multiple of 10");
+       $opt_port_base-= $rem;
+     }
+-    $opt_build_thread= $opt_port_base / 10 - 1000;
+   }
+ 
+   # --------------------------------------------------------------------------
+@@ -1719,11 +1718,6 @@ sub command_line_setup {
+ # an environment variable can be used to control all ports. A small
+ # number is to be used, 0 - 16 or similar.
+ #
+-# Note the MASTER_MYPORT has to be set the same in all 4.x and 5.x
+-# versions of this script, else a 4.0 test run might conflict with a
+-# 5.1 test run, even if different MTR_BUILD_THREAD is used. This means
+-# all port numbers might not be used in this version of the script.
+-#
+ # Also note the limitation of ports we are allowed to hand out. This
+ # differs between operating systems and configuration, see
+ # http://www.ncftp.com/ncftpd/doc/misc/ephemeral_ports.html
+@@ -1734,10 +1728,14 @@ sub set_build_thread_ports($) {
+ 
+   if ( lc($opt_build_thread) eq 'auto' ) {
+     my $found_free = 0;
+-    $build_thread = 300;	# Start attempts from here
+-    my $build_thread_upper = $build_thread + ($opt_parallel > 1500
+-                                              ? 3000
+-                                              : 2 * $opt_parallel) + 300;
++    if ($opt_port_base eq "auto") {
++      $build_thread = 15000;
++    } else {
++      $build_thread = $opt_port_base;
++    }
++    $build_thread += ($thread - 1) * $opt_port_group_size;
++    my $build_thread_upper = $build_thread + $opt_parallel * 2;
++
+     while (! $found_free)
+     {
+       $build_thread= mtr_get_unique_id($build_thread, $build_thread_upper);
+@@ -1754,7 +1752,7 @@ sub set_build_thread_ports($) {
+   }
+   else
+   {
+-    $build_thread = $opt_build_thread + $thread - 1;
++    $build_thread = $opt_port_base + $thread - 1;
+     if (! check_ports_free($build_thread)) {
+       # Some port was not free(which one has already been printed)
+       mtr_error("Some port(s) was not free")
+@@ -1763,7 +1761,7 @@ sub set_build_thread_ports($) {
+   $ENV{MTR_BUILD_THREAD}= $build_thread;
+ 
+   # Calculate baseport
+-  $baseport= $build_thread * $opt_port_group_size + 10000;
++  $baseport= $build_thread;
+   if ( $baseport < 5001 or $baseport + $opt_port_group_size >= 32767 )
+   {
+     mtr_error("MTR_BUILD_THREAD number results in a port",
+@@ -2968,7 +2966,7 @@ sub kill_leftovers ($) {
+ sub check_ports_free ($)
+ {
+   my $bthread= shift;
+-  my $portbase = $bthread * $opt_port_group_size + 10000;
++  my $portbase = $bthread;
+   for ($portbase..$portbase+($opt_port_group_size-1)){
+     if (mtr_ping_port($_)){
+       mtr_report(" - 'localhost:$_' was not free");
diff --git a/mariadb.spec b/mariadb.spec
index a7836de..2b83fd4 100644
--- a/mariadb.spec
+++ b/mariadb.spec
@@ -229,6 +229,8 @@ Patch17:          upstream_5cc2096f93b7f130b36f8bc0fc43440db9a848e4.patch
 
 #   Patch13: bundle the FMT library
 Patch13:          %{pkgnamepatch}-libfmt.patch
+#   Patch14: make MTR port calculation reasonably predictable
+Patch14:          %{pkgnamepatch}-mtr.patch
 
 BuildRequires:    cmake gcc-c++
 BuildRequires:    multilib-rpm-config
@@ -764,6 +766,7 @@ rm -r storage/rocksdb/
 %if %{with bundled_fmt}
 %patch -P13 -p1
 %endif
+%patch -P14 -p1
 # The test in Patch 10 has been recently updated by upstream
 # and the test was disabled in the testuite run
 #   main.ssl_cipher     [ disabled ]  MDEV-17184 - Failures with OpenSSL 1.1.1
@@ -1221,14 +1224,6 @@ rm %{buildroot}%{_mandir}/man1/mbstream.1*
 %check
 %if %{with test}
 %if %runselftest
-# hack to let 32- and 64-bit tests run concurrently on same build machine
-export MTR_PARALLEL=1
-# Builds might happen at the same host, avoid collision
-#   The port used is calculated as 20 * MTR_BUILD_THREAD + 10000
-#   The resulting port must be between 5000 and 32767
-#   This is the same as using option "--build-thread" for the "mysql-test-run.pl"
-export MTR_BUILD_THREAD=$(( $(date +%s) % 1100 ))
-
 # The cmake build scripts don't provide any simple way to control the
 # options for mysql-test-run, so ignore the make target and just call it
 # manually.  Nonstandard options chosen are:
@@ -1249,7 +1244,7 @@ export MTR_BUILD_THREAD=$(( $(date +%s) % 1100 ))
   set -ex
   cd %{buildroot}%{_datadir}/mysql-test
 
-  export common_testsuite_arguments=" --parallel=auto --force --retry=2 --suite-timeout=900 --testcase-timeout=30 --mysqld=--binlog-format=mixed --force-restart --shutdown-timeout=60 --max-test-fail=5 "
+  export common_testsuite_arguments=" --port-base=$(( $(date +%s) % 20000 + 10000 )) --parallel=auto --force --retry=2 --suite-timeout=900 --testcase-timeout=30 --mysqld=--binlog-format=mixed --force-restart --shutdown-timeout=60 --max-test-fail=5 "
 
   # If full testsuite has already been run on this version and we don't explicitly want the full testsuite to be run
   if [[ "%{last_tested_version}" == "%{version}" ]] && [[ %{force_run_testsuite} -eq 0 ]]