diff --git a/news.d/bugfix/1854.ui.md b/news.d/bugfix/1854.ui.md
new file mode 100644
index 000000000..c877684b8
--- /dev/null
+++ b/news.d/bugfix/1854.ui.md
@@ -0,0 +1 @@
+Fix `_pythonToCppCopy: Cannot copy-convert <set> to C++` warnings on startup.
diff --git a/plover/gui_qt/dictionaries_widget.py b/plover/gui_qt/dictionaries_widget.py
index c3787eea1..19eb78eaf 100644
--- a/plover/gui_qt/dictionaries_widget.py
+++ b/plover/gui_qt/dictionaries_widget.py
@@ -101,13 +101,13 @@ def config(self):
         def is_loaded(self):
             return self.state not in {"loading", "error"}
 
-    SUPPORTED_ROLES = {
+    SUPPORTED_ROLES = [
         Qt.ItemDataRole.AccessibleTextRole,
         Qt.ItemDataRole.CheckStateRole,
         Qt.ItemDataRole.DecorationRole,
         Qt.ItemDataRole.DisplayRole,
         Qt.ItemDataRole.ToolTipRole,
-    }
+    ]
 
     FLAGS = (
         Qt.ItemFlag.ItemIsEnabled
diff --git a/test/gui_qt/test_dictionaries_widget.py b/test/gui_qt/test_dictionaries_widget.py
index 9ad4fedba..96c1c4af8 100644
--- a/test/gui_qt/test_dictionaries_widget.py
+++ b/test/gui_qt/test_dictionaries_widget.py
@@ -35,12 +35,15 @@
 }
 ENABLED_FROM_CHAR = {c: e for e, c in ENABLED_TO_CHAR.items()}
 
-# TODO what does it mean that the MODEL_ROLES are now empty?
-MODEL_ROLES = []
-# before PySide6 refactoring:
-# MODEL_ROLES = sorted([Qt.ItemDataRole.AccessibleTextRole, Qt.ItemDataRole.CheckStateRole,
-#                      Qt.ItemDataRole.DecorationRole, Qt.ItemDataRole.DisplayRole,
-#                      Qt.ItemDataRole.ToolTipRole])
+MODEL_ROLES = sorted(
+    [
+        Qt.ItemDataRole.AccessibleTextRole,
+        Qt.ItemDataRole.CheckStateRole,
+        Qt.ItemDataRole.DecorationRole,
+        Qt.ItemDataRole.DisplayRole,
+        Qt.ItemDataRole.ToolTipRole,
+    ]
+)
 
 
 def parse_state(state_str):