diff --git a/src/widget/wtrackmenu.cpp b/src/widget/wtrackmenu.cpp
index 11bc1c7488e..e1d8a268f1b 100644
--- a/src/widget/wtrackmenu.cpp
+++ b/src/widget/wtrackmenu.cpp
@@ -782,6 +782,8 @@ std::unique_ptr<mixxx::TrackPointerIterator> WTrackMenu::newTrackPointerIterator
         if (m_trackIndexList.isEmpty()) {
             return nullptr;
         }
+        // m_pTrackModel must not be modified during the iteration,
+        // neither directly nor indirectly through signals!!!
         return std::make_unique<mixxx::TrackPointerModelIterator>(
                 m_pTrackModel,
                 m_trackIndexList);
diff --git a/src/widget/wtrackmenu.h b/src/widget/wtrackmenu.h
index cd898fa5c16..ad569cf8a78 100644
--- a/src/widget/wtrackmenu.h
+++ b/src/widget/wtrackmenu.h
@@ -137,6 +137,10 @@ class WTrackMenu : public QMenu {
 
     std::unique_ptr<mixxx::TrackPointerIterator> newTrackPointerIterator() const;
 
+    /// WARNING: The provided pTrackPointerOperation must ensure NOT
+    /// TO MODIFY the underlying m_pTrackModel during the iteration!!!
+    /// This might happen not only directly but also indirectly by
+    /// handling signals, e.g. TrackDAO::enforceModelUpdate().
     int applyTrackPointerOperation(
             const QString& progressLabelText,
             const mixxx::TrackPointerOperation* pTrackPointerOperation,