diff --git a/rfctime/rfc3339Nano.go b/rfctime/rfc3339Nano.go
index 428c8e2..7d9f16b 100644
--- a/rfctime/rfc3339Nano.go
+++ b/rfctime/rfc3339Nano.go
@@ -70,7 +70,7 @@ func (t *RFC3339NanoTime) UnmarshalBSONValue(bt bsontype.Type, data []byte) erro
 		return errors.New(fmt.Sprintf("cannot unmarshal %v into RFC3339NanoTime", bt))
 	}
 	var tt time.Time
-	err := bson.Unmarshal(data, &tt)
+	err := bson.RawValue{Type: bt, Value: data}.Unmarshal(&tt)
 	if err != nil {
 		return err
 	}