diff --git a/macosx/PiecesView.mm b/macosx/PiecesView.mm
index 7d58972b6..d5d702f9a 100644
--- a/macosx/PiecesView.mm
+++ b/macosx/PiecesView.mm
@@ -99,7 +99,7 @@ enum
     BOOL const first = std::empty(self.fPieces);
     if (first)
     {
-        self.fPieces.resize(self.fNumPieces);
+        _fPieces.resize(self.fNumPieces);
     }
 
     auto pieces = std::vector<int8_t>{};