diff --git a/java/test/ch/ntb/inf/libusbJava/test/TestLibUsbJava.java b/java/test/ch/ntb/inf/libusbJava/test/TestLibUsbJava.java
index a495590..2b4184f 100644
--- a/java/test/ch/ntb/inf/libusbJava/test/TestLibUsbJava.java
+++ b/java/test/ch/ntb/inf/libusbJava/test/TestLibUsbJava.java
@@ -120,7 +120,7 @@ public class TestLibUsbJava {
 
 		udev = LibusbJava.usb_open(dev);
 
-		if (udev != 0) {
+		if (udev <= 0) {
 			if (dev.getDescriptor().getIManufacturer() != 0) {
 				mfr = LibusbJava.usb_get_string_simple(udev, dev
 						.getDescriptor().getIManufacturer());