diff --git a/lib/jobManager.js b/lib/jobManager.js
index eeecd64..b8dc2e8 100644
--- a/lib/jobManager.js
+++ b/lib/jobManager.js
@@ -205,7 +205,13 @@ var JobManager = module.exports = function JobManager(options) {
 
         //console.log('processShare ck2')
 
-        var nTimeInt = parseInt(util.reverseBuffer(new Buffer(nTime, 'hex')), 16);
+        var nTimeInt = parseInt(util.reverseBuffer(new Buffer(nTime, 'hex')).toString('hex'), 16);
+
+	if (Number.isNaN(nTimeInt)) {
+	    // console.log('Invalid nTime: ', nTimeInt, nTime)
+	    return shareError([20, 'invalid ntime'])
+	}
+
         if (nTimeInt < job.rpcData.curtime || nTimeInt > submitTime + 7200) {
             console.log('ntime out of range');
             return shareError([20, 'ntime out of range']);