diff --git a/lib/transport/ascii.js b/lib/transport/ascii.js
index 334e07e..a62678d 100644
--- a/lib/transport/ascii.js
+++ b/lib/transport/ascii.js
@@ -63,6 +63,11 @@ Transport.prototype.unwrap = function (data) {
 		stream       : this.stream
 	};
 
+	if (unwrapped.crc != unwrapped.expected_crc) {
+		this.buffer = null;
+		return false;
+	}
+
 	if (typeof this.callback == "function") {
 		if (unwrapped.slaveId != this.callbackSlaveId) return false;