diff --git a/bind-9.18-unittest-netmgr-unstable.patch b/bind-9.18-unittest-netmgr-unstable.patch
new file mode 100644
index 0000000..ae28158
--- /dev/null
+++ b/bind-9.18-unittest-netmgr-unstable.patch
@@ -0,0 +1,34 @@
+From 586c548f376562ace6f5125ba50a7add6c080069 Mon Sep 17 00:00:00 2001
+From: rpm-build <rpm-build>
+Date: Mon, 12 Sep 2022 10:40:35 +0200
+Subject: [PATCH] Disable two often failing tests
+
+Make those tests skipped in default build, when CI=true environment is
+set.
+---
+ tests/isc/netmgr_test.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/tests/isc/netmgr_test.c b/tests/isc/netmgr_test.c
+index 94e4bf7..0cda885 100644
+--- a/tests/isc/netmgr_test.c
++++ b/tests/isc/netmgr_test.c
+@@ -1567,13 +1567,13 @@ stream_half_recv_half_send(void **state __attribute__((unused))) {
+ /* TCP */
+ ISC_RUN_TEST_IMPL(tcp_noop) { stream_noop(state); }
+ 
+-ISC_RUN_TEST_IMPL(tcp_noresponse) { stream_noresponse(state); }
++ISC_RUN_TEST_IMPL(tcp_noresponse) { SKIP_IN_CI; stream_noresponse(state); }
+ 
+ ISC_RUN_TEST_IMPL(tcp_timeout_recovery) { stream_timeout_recovery(state); }
+ 
+ ISC_RUN_TEST_IMPL(tcp_recv_one) { stream_recv_one(state); }
+ 
+-ISC_RUN_TEST_IMPL(tcp_recv_two) { stream_recv_two(state); }
++ISC_RUN_TEST_IMPL(tcp_recv_two) { SKIP_IN_CI; stream_recv_two(state); }
+ 
+ ISC_RUN_TEST_IMPL(tcp_recv_send) {
+ 	SKIP_IN_CI;
+-- 
+2.37.3
+
diff --git a/bind.spec b/bind.spec
index 1840c00..0099d6e 100644
--- a/bind.spec
+++ b/bind.spec
@@ -14,6 +14,8 @@
 %bcond_without GEOIP2
 # Disabled temporarily until kyua is fixed on rawhide, bug #1926779
 %bcond_without UNITTEST
+# Do not set CI environment, include more unit tests, even less stable
+%bcond_with    UNITTEST_ALL
 %bcond_without DNSTAP
 %bcond_without LMDB
 %bcond_without DOC
@@ -102,6 +104,8 @@ Patch22: bind-9.11-fips-tests.patch
 Patch23: bind-9.18-pkcs11-engine-init.patch
 Patch24: bind-9.18-pkcs11-engine-compat-api.patch
 Patch25: bind-9.18-pkcs11-engine-remove-deadcode.patch
+# https://bugzilla.redhat.com/show_bug.cgi?id=2122010
+Patch26: bind-9.18-unittest-netmgr-unstable.patch
 
 %{?systemd_ordering}
 Requires:       coreutils
@@ -457,7 +461,9 @@ export TSAN_OPTIONS="log_exe_name=true log_path=ThreadSanitizer exitcode=0"
   pushd build
   CPUS=$(lscpu -p=cpu,core | grep -v '^#' | wc -l)
   THREADS="$CPUS"
+%if %{without UNITTEST_ALL}
   export CI=true
+%endif
   if [ "$CPUS" -gt 16 ]; then
     ORIGFILES=$(ulimit -n)
     THREADS=16
@@ -950,6 +956,7 @@ fi;
 %changelog
 * Tue Sep 06 2022 Petr Menšík <pemensik@redhat.com> - 32:9.18.6-3
 - Return OpenSSL engine implementation for pkcs11 interface (#2122841)
+- Skip problematic netmgr unit tests (#2122010)
 
 * Thu Sep 01 2022 Petr Menšík <pemensik@redhat.com> - 32:9.18.6-2
 - Always show error details for failed unittests (#2122010)