diff --git a/bind-9.16-unit-tests-multicore.patch b/bind-9.16-unit-tests-multicore.patch
new file mode 100644
index 0000000..8ca0448
--- /dev/null
+++ b/bind-9.16-unit-tests-multicore.patch
@@ -0,0 +1,84 @@
+From 0175b942efc2fb6a05a2c76d62a9fb9157141757 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
+Date: Wed, 20 Jan 2021 01:01:52 +0100
+Subject: [PATCH] Workaround errors in unit test on 56 CPU machine
+
+hp.c should be just implementation detail, but unit tests use it
+repeatedly without resetting tid_v_base. Reset the base counter, when
+number of processors is configured. Configure it when creating network
+manager.
+
+Use id of current thread as a base. Should be usually 0, but must not be
+below id of the main thread.
+---
+ bin/named/main.c        | 7 -------
+ lib/isc/hp.c            | 1 +
+ lib/isc/netmgr/netmgr.c | 8 ++++++++
+ 3 files changed, 9 insertions(+), 7 deletions(-)
+
+diff --git a/bin/named/main.c b/bin/named/main.c
+index 9836de9d7f..d1be43a632 100644
+--- a/bin/named/main.c
++++ b/bin/named/main.c
+@@ -24,7 +24,6 @@
+ #include <isc/dir.h>
+ #include <isc/file.h>
+ #include <isc/hash.h>
+-#include <isc/hp.h>
+ #include <isc/httpd.h>
+ #include <isc/netmgr.h>
+ #include <isc/os.h>
+@@ -909,12 +908,6 @@ create_managers(void) {
+ 		      "using %u UDP listener%s per interface", named_g_udpdisp,
+ 		      named_g_udpdisp == 1 ? "" : "s");
+ 
+-	/*
+-	 * We have ncpus network threads, ncpus worker threads, ncpus
+-	 * old network threads - make it 4x just to be safe. The memory
+-	 * impact is negligible.
+-	 */
+-	isc_hp_init(4 * named_g_cpus);
+ 	named_g_nm = isc_nm_start(named_g_mctx, named_g_cpus);
+ 	if (named_g_nm == NULL) {
+ 		UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_nm_start() failed");
+diff --git a/lib/isc/hp.c b/lib/isc/hp.c
+index 3ea13bbe24..e4a98afc82 100644
+--- a/lib/isc/hp.c
++++ b/lib/isc/hp.c
+@@ -95,6 +95,7 @@ void
+ isc_hp_init(int max_threads) {
+ 	isc__hp_max_threads = max_threads;
+ 	isc__hp_max_retired = max_threads * HP_MAX_HPS;
++	atomic_store_release(&tid_v_base, tid());
+ }
+ 
+ isc_hp_t *
+diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
+index 46f0758620..e3469f4c3a 100644
+--- a/lib/isc/netmgr/netmgr.c
++++ b/lib/isc/netmgr/netmgr.c
+@@ -17,6 +17,7 @@
+ #include <isc/buffer.h>
+ #include <isc/condition.h>
+ #include <isc/errno.h>
++#include <isc/hp.h>
+ #include <isc/magic.h>
+ #include <isc/mem.h>
+ #include <isc/netmgr.h>
+@@ -238,6 +239,13 @@ isc_nm_start(isc_mem_t *mctx, uint32_t workers) {
+ 	atomic_init(&mgr->keepalive, 30000);
+ 	atomic_init(&mgr->advertised, 30000);
+ 
++	/*
++	 * We have ncpus network threads, ncpus worker threads, ncpus
++	 * old network threads - make it 4x just to be safe. The memory
++	 * impact is negligible.
++	 */
++	isc_hp_init(4 * workers);
++
+ 	isc_mutex_init(&mgr->reqlock);
+ 	isc_mempool_create(mgr->mctx, sizeof(isc__nm_uvreq_t), &mgr->reqpool);
+ 	isc_mempool_setname(mgr->reqpool, "nm_reqpool");
+-- 
+2.26.2
+
diff --git a/bind.spec b/bind.spec
index a4017f4..989efb9 100644
--- a/bind.spec
+++ b/bind.spec
@@ -118,6 +118,8 @@ Patch157:bind-9.11-fips-tests.patch
 Patch164:bind-9.11-rh1666814.patch
 Patch170:bind-9.11-feature-test-named.patch
 Patch171:bind-9.11-tests-variants.patch
+# https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/4582
+Patch172:bind-9.16-unit-tests-multicore.patch
 
 Requires(post):   systemd
 Requires(preun):  systemd
@@ -431,6 +433,7 @@ in HTML and PDF format.
 %patch164 -p1 -b .rh1666814
 %patch170 -p1 -b .featuretest-named
 %patch171 -p1 -b .test-variant
+%patch172 -p1 -b .multicore
 
 %if %{with PKCS11}
 %patch135 -p1 -b .config-pkcs11
@@ -1157,6 +1160,7 @@ fi;
 %changelog
 * Thu Jan 21 2021 Petr Menšík <pemensik@redhat.com> - 32:9.16.11-1
 - Update to 9.16.11 (#1827602)
+- Avoid unit test failures on machines with many cores
 
 * Thu Jan 14 2021 Petr Menšík <pemensik@redhat.com> - 32:9.16.10-2
 - Update to 9.16.10