diff --git a/translate.go b/translate.go
index a01d7f2e2..ea268bb68 100644
--- a/translate.go
+++ b/translate.go
@@ -415,19 +415,19 @@ func (s *InMemTranslateStore) EntryReader(ctx context.Context, offset uint64) (T
 }
 
 // WriteTo ensures that the TranslateStore implements io.WriterTo.
-// TODO: It's not important that this be implemented. It would really
+// It's not important that this be implemented. It would really
 // only be necessary if we wanted to test cluster resizing while using
 // an in-memory translate store.
 func (s *InMemTranslateStore) WriteTo(w io.Writer) (int64, error) {
-	return 0, nil
+	return 0, ErrNotImplemented
 }
 
 // ReadFrom ensures that the TranslateStore implements io.ReaderFrom.
-// TODO: It's not important that this be implemented. It would really
+// It's not important that this be implemented. It would really
 // only be necessary if we wanted to test cluster resizing while using
 // an in-memory translate store.
 func (s *InMemTranslateStore) ReadFrom(r io.Reader) (int64, error) {
-	return 0, nil
+	return 0, ErrNotImplemented
 }
 
 // MaxID returns the highest identifier in the store.