diff --git a/bacnet-stack/ports/pic18f6720/mstp.c b/bacnet-stack/ports/pic18f6720/mstp.c
index de38f555..775cd18a 100644
--- a/bacnet-stack/ports/pic18f6720/mstp.c
+++ b/bacnet-stack/ports/pic18f6720/mstp.c
@@ -1166,7 +1166,7 @@ bool MSTP_Master_Node_FSM(
                     (uint8_t *) & mstp_port->TxBuffer[0], mstp_port->TxLength);
                 mstp_port->TxReady = false;
                 mstp_port->master_state = MSTP_MASTER_STATE_IDLE;
-            } else {
+            } else if (mstp_port->SilenceTimer > Treply_delay) {
                 /* DeferredReply */
                 /* If no reply will be available from the higher layers */
                 /* within Treply_delay after the reception of the */