diff --git a/development/src/main/java/gurux/serial/GXSerial.java b/development/src/main/java/gurux/serial/GXSerial.java
index 72c66c2..83c1d8e 100644
--- a/development/src/main/java/gurux/serial/GXSerial.java
+++ b/development/src/main/java/gurux/serial/GXSerial.java
@@ -943,6 +943,10 @@ public final long getBytesSent() {
 
     @Override
     public final long getBytesReceived() {
+        if(this.receiver == null)
+        {
+            return 0;
+        }
         return receiver.getBytesReceived();
     }
 
@@ -1140,4 +1144,4 @@ public void setAsyncWaitTime(final int value) {
     public Object getAsyncWaitHandle() {
         return null;
     }
-}
\ No newline at end of file
+}