diff --git a/usb/constants.go b/usb/constants.go
index b83c2d3..8a25984 100644
--- a/usb/constants.go
+++ b/usb/constants.go
@@ -147,3 +147,23 @@ var isoUsageTypeDescription = map[IsoUsageType]string{
 func (iut IsoUsageType) String() string {
 	return isoUsageTypeDescription[iut]
 }
+
+type RequestType uint8
+
+const (
+	REQUEST_TYPE_STANDARD = C.LIBUSB_REQUEST_TYPE_STANDARD
+	REQUEST_TYPE_CLASS    = C.LIBUSB_REQUEST_TYPE_CLASS
+	REQUEST_TYPE_VENDOR   = C.LIBUSB_REQUEST_TYPE_VENDOR
+	REQUEST_TYPE_RESERVED = C.LIBUSB_REQUEST_TYPE_RESERVED
+)
+
+var requestTypeDescription = map[RequestType]string{
+	REQUEST_TYPE_STANDARD: "standard",
+	REQUEST_TYPE_CLASS:    "class",
+	REQUEST_TYPE_VENDOR:   "vendor",
+	REQUEST_TYPE_RESERVED: "reserved",
+}
+
+func (rt RequestType) String() string {
+	return requestTypeDescription[rt]
+}
diff --git a/usb/device.go b/usb/device.go
index 1264e65..bd39ce1 100644
--- a/usb/device.go
+++ b/usb/device.go
@@ -157,8 +157,14 @@ func (d *Device) OpenEndpoint(conf, iface, setup, epoint uint8) (Endpoint, error
 found:
 
 	// Set the configuration
-	if errno := C.libusb_set_configuration(d.handle, C.int(conf)); errno < 0 {
-		return nil, fmt.Errorf("usb: setcfg: %s", usbError(errno))
+	var activeConf C.int
+	if errno := C.libusb_get_configuration(d.handle, &activeConf); errno < 0 {
+		return nil, fmt.Errorf("usb: getcfg: %s", usbError(errno))
+	}
+	if int(activeConf) != int(conf) {
+		if errno := C.libusb_set_configuration(d.handle, C.int(conf)); errno < 0 {
+			return nil, fmt.Errorf("usb: setcfg: %s", usbError(errno))
+		}
 	}
 
 	// Claim the interface