diff --git a/lib/modem.js b/lib/modem.js
index be3d22e..1e1822b 100644
--- a/lib/modem.js
+++ b/lib/modem.js
@@ -6,7 +6,7 @@ const INTERVAL_BEETWEN_SIGNAL_STRENGTH_MS = 60000;
 const REGEX_WAIT_FOR_OK_OR_ERROR = /\n(?:OK|ERROR)\r\n/;
 // const REGEX_WAIT_FOR_OK_OR_ERROR = /\nOK\r\n/;
 
-const MAX_LAST_DATA_AGE_MS = 3 * 60 * 100;
+const MAX_LAST_DATA_AGE_MS = 3 * 60 * 1000;
 
 const moment = require('moment');
 const SerialPort = require('serialport');