diff --git a/lib/dns/client.c b/lib/dns/client.c
index 2dafddea72..bbf9031700 100644
--- a/lib/dns/client.c
+++ b/lib/dns/client.c
@@ -1035,7 +1035,6 @@ dns_client_resolve(dns_client_t *client, const dns_name_t *name,
 
 	resarg = isc_mem_get(client->mctx, sizeof(*resarg));
 
-	isc_mutex_init(&resarg->lock);
 	*resarg = (resarg_t){
 		.actx = client->actx,
 		.client = client,
@@ -1043,6 +1042,8 @@ dns_client_resolve(dns_client_t *client, const dns_name_t *name,
 		.namelist = namelist,
 	};
 
+	isc_mutex_init(&resarg->lock);
+
 	result = dns_client_startresolve(client, name, rdclass, type, options,
 					 client->task, resolve_done, resarg,
 					 &resarg->trans);