diff --git a/NTPClient.h b/NTPClient.h
index 4d5630d..e35707d 100644
--- a/NTPClient.h
+++ b/NTPClient.h
@@ -25,6 +25,7 @@ class NTPClient {
     byte          _packetBuffer[NTP_PACKET_SIZE];
 
     void          sendNTPPacket();
+    bool          isValid(byte * ntpPacket);
 
   public:
     NTPClient(UDP& udp);