diff --git a/serialworker.cpp b/serialworker.cpp
index de2ec11..bab78a2 100644
--- a/serialworker.cpp
+++ b/serialworker.cpp
@@ -30,7 +30,7 @@ SerialWorker::~SerialWorker()
         serial->disconnect(); //disconnect all signals
         delete serial;
     }
-    ticker->stop();
+    if (ticker != NULL) ticker->stop();
 }
 
 void SerialWorker::setSerialPort(QSerialPortInfo *port)