diff --git a/usb/constants.go b/usb/constants.go
index a71a9fd..4ff0ef2 100644
--- a/usb/constants.go
+++ b/usb/constants.go
@@ -179,13 +179,13 @@ const (
 	// Note: USB3.0 defines usage type for both isochronous and interrupt
 	// endpoints, with the same constants representing different usage types.
 	// UsageType constants do not correspond to bmAttribute values.
-	usageTypeMask                = 0x30
 	UsageTypeUndefined UsageType = iota
 	IsoUsageTypeData
 	IsoUsageTypeFeedback
 	IsoUsageTypeImplicit
 	InterruptUsageTypePeriodic
 	InterruptUsageTypeNotification
+	usageTypeMask = 0x30
 )
 
 var usageTypeDescription = map[UsageType]string{