diff --git a/CHANGES b/CHANGES
index be6f6961a8..882a14f464 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4033.	[bug]		Missing out of memory check in request.c:req_send.
+			[RT #38311]
+
 4032.	[bug]		Built-in "empty" zones did not correctly inherit the
 			"allow-transfer" ACL from the options or view.
 			[RT #38310]
diff --git a/lib/dns/request.c b/lib/dns/request.c
index 72b8d51a87..98907fe6a6 100644
--- a/lib/dns/request.c
+++ b/lib/dns/request.c
@@ -444,6 +444,8 @@ req_send(dns_request_t *request, isc_task_t *task, isc_sockaddr_t *address) {
 	sendevent = isc_socket_socketevent(request->mctx, socket,
 					   ISC_SOCKEVENT_SENDDONE,
 					   req_senddone, request);
+	if (sendevent == NULL)
+		return (ISC_R_NOMEMORY);
 	if (request->dscp == -1) {
 		sendevent->attributes &= ~ISC_SOCKEVENTATTR_DSCP;
 		sendevent->dscp = 0;