diff --git a/bind-9.16-rhbz2088125.patch b/bind-9.16-rhbz2088125.patch
new file mode 100644
index 0000000..0ac3a99
--- /dev/null
+++ b/bind-9.16-rhbz2088125.patch
@@ -0,0 +1,66 @@
+From 1feb389f80f7595d2f873c3ff8678b52cd2db828 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
+Date: Tue, 24 May 2022 19:42:41 +0200
+Subject: [PATCH] Fix failures in isc netmgr_test on big endian machines
+
+Typing from libuv structure to isc_region_t is not possible, because
+their sizes differ on 64 bit architectures. Little endian machines seems
+to be lucky and still result in test passed. But big endian machine such
+as s390x fails the test reliably.
+
+Fix by directly creating the buffer as isc_region_t and skipping the
+type conversion. More readable and still more correct.
+
+(cherry picked from commit 057438cb45f2f02615dc309e3822f23c0ca70a0a)
+---
+ lib/isc/tests/netmgr_test.c | 18 ++++++++----------
+ 1 file changed, 8 insertions(+), 10 deletions(-)
+
+diff --git a/lib/isc/tests/netmgr_test.c b/lib/isc/tests/netmgr_test.c
+index c2d7fffb32..9fa0d47e5b 100644
+--- a/lib/isc/tests/netmgr_test.c
++++ b/lib/isc/tests/netmgr_test.c
+@@ -62,11 +62,11 @@ static isc_sockaddr_t tcp_connect_addr;
+ static uint64_t send_magic = 0;
+ static uint64_t stop_magic = 0;
+ 
+-static uv_buf_t send_msg = { .base = (char *)&send_magic,
+-			     .len = sizeof(send_magic) };
++static isc_region_t send_msg = { .base = (unsigned char *)&send_magic,
++				 .length = sizeof(send_magic) };
+ 
+-static uv_buf_t stop_msg = { .base = (char *)&stop_magic,
+-			     .len = sizeof(stop_magic) };
++static isc_region_t stop_msg = { .base = (unsigned char *)&stop_magic,
++				 .length = sizeof(stop_magic) };
+ 
+ static atomic_bool do_send = false;
+ static unsigned int workers = 0;
+@@ -420,11 +420,9 @@ connect_send(isc_nmhandle_t *handle) {
+ 	isc_nmhandle_attach(handle, &sendhandle);
+ 	isc_nmhandle_setwritetimeout(handle, T_IDLE);
+ 	if (atomic_fetch_sub(&nsends, 1) > 1) {
+-		isc_nm_send(sendhandle, (isc_region_t *)&send_msg,
+-			    connect_send_cb, NULL);
++		isc_nm_send(sendhandle, &send_msg, connect_send_cb, NULL);
+ 	} else {
+-		isc_nm_send(sendhandle, (isc_region_t *)&stop_msg,
+-			    connect_send_cb, NULL);
++		isc_nm_send(sendhandle, &stop_msg, connect_send_cb, NULL);
+ 	}
+ }
+ 
+@@ -531,8 +529,8 @@ listen_read_cb(isc_nmhandle_t *handle, isc_result_t eresult,
+ 			isc_nmhandle_attach(handle, &sendhandle);
+ 			isc_refcount_increment0(&active_ssends);
+ 			isc_nmhandle_setwritetimeout(sendhandle, T_IDLE);
+-			isc_nm_send(sendhandle, (isc_region_t *)&send_msg,
+-				    listen_send_cb, cbarg);
++			isc_nm_send(sendhandle, &send_msg, listen_send_cb,
++				    cbarg);
+ 		}
+ 		return;
+ 	}
+-- 
+2.34.3
+
diff --git a/bind.spec b/bind.spec
index 0f72831..77c13d1 100644
--- a/bind.spec
+++ b/bind.spec
@@ -107,6 +107,8 @@ Patch26: bind-9.16-locked-isc-queue.patch
 # https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/5273
 Patch27: bind-9.16-resolv.conf-options-timeout.patch
 Patch28: bind-9.16-resolv.conf-options-timeout-test.patch
+# https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/6352
+Patch29: bind-9.16-rhbz2088125.patch
 
 %{?systemd_ordering}
 Requires:       coreutils
@@ -1119,6 +1121,7 @@ fi;
 %changelog
 * Thu May 26 2022 Petr Menšík <pemensik@redhat.com> - 32:9.16.29-1
 - Update to 9.16.29 (#2087920)
+- Fix netmgr_test fails on s390x (#2088125)
 
 * Tue May 17 2022 Petr Menšík <pemensik@redhat.com> - 32:9.16.28-2
 - Parse again timeout and attempts from resolv.conf (#2087156)