diff --git a/src/Gui/DlgExpressionInput.cpp b/src/Gui/DlgExpressionInput.cpp
index 46f31b7293..2d8b5717f7 100644
--- a/src/Gui/DlgExpressionInput.cpp
+++ b/src/Gui/DlgExpressionInput.cpp
@@ -66,7 +66,11 @@ DlgExpressionInput::DlgExpressionInput(const App::ObjectIdentifier & _path,
     DocumentObject * docObj = path.getDocumentObject();
     ui->expression->setDocumentObject(docObj);
 
+#if defined(Q_OS_MAC)
+    setWindowFlags(Qt::Widget | Qt::Popup | Qt::FramelessWindowHint);
+#else
     setWindowFlags(Qt::SubWindow | Qt::Widget | Qt::Popup | Qt::FramelessWindowHint);
+#endif
     setAttribute(Qt::WA_NoSystemBackground, true);
     setAttribute(Qt::WA_TranslucentBackground, true);