diff --git a/bin/classes/com/felhr/usbserial/UsbSerialDevice$ReadThread.class b/bin/classes/com/felhr/usbserial/UsbSerialDevice$ReadThread.class
index 58dc056..2b7b315 100644
Binary files a/bin/classes/com/felhr/usbserial/UsbSerialDevice$ReadThread.class and b/bin/classes/com/felhr/usbserial/UsbSerialDevice$ReadThread.class differ
diff --git a/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class b/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class
index 62b28ea..5151bc0 100644
Binary files a/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class and b/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class differ
diff --git a/bin/classes/com/felhr/usbserial/UsbSerialDevice$WriteThread.class b/bin/classes/com/felhr/usbserial/UsbSerialDevice$WriteThread.class
index c1fe96a..76c4583 100644
Binary files a/bin/classes/com/felhr/usbserial/UsbSerialDevice$WriteThread.class and b/bin/classes/com/felhr/usbserial/UsbSerialDevice$WriteThread.class differ
diff --git a/bin/classes/com/felhr/usbserial/UsbSerialDevice.class b/bin/classes/com/felhr/usbserial/UsbSerialDevice.class
index 6589db3..49a8fc3 100644
Binary files a/bin/classes/com/felhr/usbserial/UsbSerialDevice.class and b/bin/classes/com/felhr/usbserial/UsbSerialDevice.class differ
diff --git a/bin/usbserial.jar b/bin/usbserial.jar
index 2253357..7b693bb 100644
Binary files a/bin/usbserial.jar and b/bin/usbserial.jar differ
diff --git a/src/com/felhr/usbserial/UsbSerialDevice.java b/src/com/felhr/usbserial/UsbSerialDevice.java
index 5793cd8..50065cf 100644
--- a/src/com/felhr/usbserial/UsbSerialDevice.java
+++ b/src/com/felhr/usbserial/UsbSerialDevice.java
@@ -10,6 +10,7 @@ import android.hardware.usb.UsbConstants;
 import android.hardware.usb.UsbDevice;
 import android.hardware.usb.UsbDeviceConnection;
 import android.hardware.usb.UsbEndpoint;
+import android.hardware.usb.UsbInterface;
 import android.hardware.usb.UsbRequest;
 
 public abstract class UsbSerialDevice implements UsbSerialInterface
@@ -69,8 +70,10 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 			return new CP2102SerialDevice(device, connection);
 		else if(PL2303Ids.isDeviceSupported(vid, pid))
 			return new PL2303SerialDevice(device, connection);
-		else  
+		else if(isCdcDevice(device))  
 			return new CDCSerialDevice(device, connection);
+		else 
+			return null;
 	}
 	
 	// Common Usb Serial Operations (I/O Asynchronous)
@@ -126,6 +129,18 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 		return (this instanceof FTDISerialDevice);
 	}
 	
+	private static boolean isCdcDevice(UsbDevice device)
+	{
+		int iIndex = device.getInterfaceCount();
+		for(int i=0;i<=iIndex-1;i++)
+		{
+			UsbInterface iface = device.getInterface(i);
+			if(iface.getInterfaceClass() == UsbConstants.USB_CLASS_CDC_DATA)
+				return true;
+		}
+		return false;
+	}
+	
 	
 	/*
 	 * WorkerThread waits for request notifications from IN endpoint