diff --git a/src/rsrv/camessage.c b/src/rsrv/camessage.c
index 160bc2138..44346ec77 100644
--- a/src/rsrv/camessage.c
+++ b/src/rsrv/camessage.c
@@ -2528,8 +2528,10 @@ int camessage ( struct client *client )
          * aligned payloads
          */
         if ( msgsize & 0x7 ) {
+                SEND_LOCK(client);
             send_err ( &msg, ECA_INTERNAL, client, 
                 "CAS: Missaligned protocol rejected" );
+                SEND_UNLOCK(client);
             log_header ( "CAS: Missaligned protocol rejected", 
                 client, &msg, 0, nmsg );
             status = RSRV_ERROR;
@@ -2545,9 +2547,11 @@ int camessage ( struct client *client )
         if ( msgsize > client->recv.maxstk ) {
             casExpandRecvBuffer ( client, msgsize );
             if ( msgsize > client->recv.maxstk ) {
+                    SEND_LOCK(client);
                 send_err ( &msg, ECA_TOLARGE, client, 
                     "CAS: Server unable to load large request message. Max bytes=%lu",
                     rsrvSizeofLargeBufTCP );
+                    SEND_UNLOCK(client);
                 log_header ( "CAS: server unable to load large request message", 
                     client, &msg, 0, nmsg );
                 assert ( client->recv.cnt <= client->recv.maxstk );