diff --git a/vendor/github.com/gogo/protobuf/proto/table_marshal.go b/vendor/github.com/gogo/protobuf/proto/table_marshal.go
index 9b1538d..db9927a 100644
--- a/vendor/github.com/gogo/protobuf/proto/table_marshal.go
+++ b/vendor/github.com/gogo/protobuf/proto/table_marshal.go
@@ -389,8 +389,13 @@
 	// get oneof implementers
 	var oneofImplementers []interface{}
 	// gogo: isOneofMessage is needed for embedded oneof messages, without a marshaler and unmarshaler
-	if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(oneofMessage); ok && isOneofMessage {
-		_, _, _, oneofImplementers = m.XXX_OneofFuncs()
+	if isOneofMessage {
+		switch m := reflect.Zero(reflect.PtrTo(t)).Interface().(type) {
+		case oneofFuncsIface:
+			_, _, _, oneofImplementers = m.XXX_OneofFuncs()
+		case oneofWrappersIface:
+			oneofImplementers = m.XXX_OneofWrappers()
+		}
 	}
 
 	// normal fields
@@ -519,10 +524,6 @@
 	}
 }
 
-type oneofMessage interface {
-	XXX_OneofFuncs() (func(Message, *Buffer) error, func(Message, int, int, *Buffer) (bool, error), func(Message) int, []interface{})
-}
-
 // wiretype returns the wire encoding of the type.
 func wiretype(encoding string) uint64 {
 	switch encoding {