diff --git a/CHANGES b/CHANGES
index 6e8edb7cec..01f3f41adf 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4536.	[bug]		ISC_SOCKEVENTATTR_USEMINMTU was not being cleared
+			when reusing the event structure. [RT #43885]
+
 4535.	[bug]		Address race condition in setting / testing of
 			DNS_REQUEST_F_SENDING. [RT #43889]
 
diff --git a/bin/named/client.c b/bin/named/client.c
index 1b6388e4b3..89721a7e7d 100644
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -929,6 +929,7 @@ client_sendpkg(ns_client_t *client, isc_buffer_t *buffer) {
 	 * MTU link force fragmentation at 1280 if it is a IPv6
 	 * response.
 	 */
+	client->sendevent->attributes &= ~ISC_SOCKEVENTATTR_USEMINMTU;
 	if (!TCP_CLIENT(client) && r.length > 1432)
 		client->sendevent->attributes |= ISC_SOCKEVENTATTR_USEMINMTU;