diff --git a/usb/config.go b/usb/config.go
index 95a0669..43624c0 100644
--- a/usb/config.go
+++ b/usb/config.go
@@ -81,12 +81,12 @@ type InterfaceSetup struct {
 	Number uint8
 	// Alternate is the number of the alternate setting.
 	Alternate uint8
-	// IfClass is the USB-IF class code, as defined by the USB spec.
-	IfClass Class
-	// IfClass is the USB-IF subclass code, as defined by the USB spec.
-	IfSubClass Class
-	// IfProtocol is USB protocol code, as defined by the USB spe.c
-	IfProtocol Protocol
+	// Class is the USB-IF class code, as defined by the USB spec.
+	Class Class
+	// SubClass is the USB-IF subclass code, as defined by the USB spec.
+	SubClass Class
+	// Protocol is USB protocol code, as defined by the USB spe.c
+	Protocol Protocol
 	// Endpoints has the list of endpoints available on this interface with
 	// this alternate setting.
 	Endpoints []EndpointInfo
diff --git a/usb/endpoint_info_test.go b/usb/endpoint_info_test.go
index 9063168..702c8c4 100644
--- a/usb/endpoint_info_test.go
+++ b/usb/endpoint_info_test.go
@@ -27,7 +27,7 @@ var testBulkInEP = EndpointInfo{
 var testBulkInSetup = InterfaceSetup{
 	Number:    0,
 	Alternate: 0,
-	IfClass:   ClassVendorSpec,
+	Class:     ClassVendorSpec,
 	Endpoints: []EndpointInfo{testBulkInEP},
 }
 
@@ -43,6 +43,6 @@ var testIsoOutEP = EndpointInfo{
 var testIsoOutSetup = InterfaceSetup{
 	Number:    0,
 	Alternate: 0,
-	IfClass:   ClassVendorSpec,
+	Class:     ClassVendorSpec,
 	Endpoints: []EndpointInfo{testIsoOutEP},
 }
diff --git a/usb/fakelibusb_test.go b/usb/fakelibusb_test.go
index 0052c92..bcfd512 100644
--- a/usb/fakelibusb_test.go
+++ b/usb/fakelibusb_test.go
@@ -37,13 +37,13 @@ var (
 			Protocol: 255,
 			Configs: []ConfigInfo{{
 				Config:   1,
-				MaxPower: 50, // * 2mA
+				MaxPower: Milliamperes(100),
 				Interfaces: []InterfaceInfo{{
 					Number: 0,
 					Setups: []InterfaceSetup{{
 						Number:    0,
 						Alternate: 0,
-						IfClass:   ClassVendorSpec,
+						Class:     ClassVendorSpec,
 						Endpoints: []EndpointInfo{{
 							Number:        1,
 							Direction:     EndpointDirectionOut,
@@ -73,20 +73,20 @@ var (
 			Protocol: 255,
 			Configs: []ConfigInfo{{
 				Config:   1,
-				MaxPower: 50, // * 2mA
+				MaxPower: Milliamperes(100),
 				Interfaces: []InterfaceInfo{{
 					Number: 0,
 					Setups: []InterfaceSetup{{
 						Number:    0,
 						Alternate: 0,
-						IfClass:   ClassVendorSpec,
+						Class:     ClassVendorSpec,
 					}},
 				}, {
 					Number: 1,
 					Setups: []InterfaceSetup{{
 						Number:    1,
 						Alternate: 0,
-						IfClass:   ClassVendorSpec,
+						Class:     ClassVendorSpec,
 						Endpoints: []EndpointInfo{{
 							Number:        5,
 							Direction:     EndpointDirectionOut,
@@ -103,7 +103,7 @@ var (
 					}, {
 						Number:    1,
 						Alternate: 1,
-						IfClass:   ClassVendorSpec,
+						Class:     ClassVendorSpec,
 						Endpoints: []EndpointInfo{{
 							Number:        5,
 							Direction:     EndpointDirectionOut,
@@ -118,7 +118,7 @@ var (
 					}, {
 						Number:    1,
 						Alternate: 2,
-						IfClass:   ClassVendorSpec,
+						Class:     ClassVendorSpec,
 						Endpoints: []EndpointInfo{{
 							Number:        5,
 							Direction:     EndpointDirectionIn,
diff --git a/usb/libusb.go b/usb/libusb.go
index e7c6dd3..5950618 100644
--- a/usb/libusb.go
+++ b/usb/libusb.go
@@ -241,11 +241,11 @@ func (libusbImpl) getDeviceDesc(d *libusbDevice) (*Descriptor, error) {
 			descs := make([]InterfaceSetup, 0, len(alts))
 			for _, alt := range alts {
 				i := InterfaceSetup{
-					Number:     uint8(alt.bInterfaceNumber),
-					Alternate:  uint8(alt.bAlternateSetting),
-					IfClass:    Class(alt.bInterfaceClass),
-					IfSubClass: Class(alt.bInterfaceSubClass),
-					IfProtocol: Protocol(alt.bInterfaceProtocol),
+					Number:    uint8(alt.bInterfaceNumber),
+					Alternate: uint8(alt.bAlternateSetting),
+					Class:     Class(alt.bInterfaceClass),
+					SubClass:  Class(alt.bInterfaceSubClass),
+					Protocol:  Protocol(alt.bInterfaceProtocol),
 				}
 				var ends []C.struct_libusb_endpoint_descriptor
 				*(*reflect.SliceHeader)(unsafe.Pointer(&ends)) = reflect.SliceHeader{
diff --git a/usbid/describe.go b/usbid/describe.go
index c3dbc8c..7ba6855 100644
--- a/usbid/describe.go
+++ b/usbid/describe.go
@@ -64,7 +64,7 @@ func Classify(val interface{}) string {
 	case *usb.Descriptor:
 		class, sub, proto = val.Class, val.SubClass, val.Protocol
 	case usb.InterfaceSetup:
-		class, sub, proto = usb.Class(val.IfClass), usb.Class(val.IfSubClass), val.IfProtocol
+		class, sub, proto = val.Class, val.SubClass, val.Protocol
 	default:
 		return fmt.Sprintf("Unknown (%T)", val)
 	}