diff --git a/bind-9.21-unittest-isc-time-32b.patch b/bind-9.21-unittest-isc-time-32b.patch
new file mode 100644
index 0000000..4f1dcee
--- /dev/null
+++ b/bind-9.21-unittest-isc-time-32b.patch
@@ -0,0 +1,25 @@
+From 18ecdde54b42d1d4fe7583736269974356b00287 Mon Sep 17 00:00:00 2001
+From: Petr Mensik <pemensik@redhat.com>
+Date: Wed, 20 Nov 2024 13:03:07 +0100
+Subject: [PATCH] Fix unit test build on 32 bit architecture
+
+---
+ tests/isc/time_test.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tests/isc/time_test.c b/tests/isc/time_test.c
+index d3a7c01..26d2775 100644
+--- a/tests/isc/time_test.c
++++ b/tests/isc/time_test.c
+@@ -280,7 +280,7 @@ ISC_RUN_TEST_IMPL(isc_time_formatISO8601TZms_test) {
+ 	assert_int_equal(buf[16], ':');
+ 	assert_int_equal(buf[19], '.');
+ 
+-	size_t plus_minus[2] = { '+', '-' };
++	LargestIntegralType plus_minus[2] = { '+', '-' };
+ 	assert_in_set(buf[23], plus_minus, sizeof(plus_minus));
+ 	assert_int_equal(buf[26], ':');
+ 
+-- 
+2.47.0
+
diff --git a/bind9-next.spec b/bind9-next.spec
index f59fb53..735c56c 100644
--- a/bind9-next.spec
+++ b/bind9-next.spec
@@ -92,6 +92,8 @@ Source49: named-chroot.files
 # Common patches
 # Red Hat specific documentation is not relevant to upstream
 Patch1: bind-9.16-redhat_doc.patch
+# https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/9753
+Patch2: bind-9.21-unittest-isc-time-32b.patch
 
 %{?systemd_ordering}
 Requires:       coreutils