diff --git a/app/portal/list.py b/app/portal/list.py
index 54ffb80..a2d4f03 100644
--- a/app/portal/list.py
+++ b/app/portal/list.py
@@ -85,9 +85,9 @@ def list_destroy(list_id: int) -> ResponseReturnValue:
 @bp.route("/new/<group_id>", methods=['GET', 'POST'])
 def list_new(group_id: Optional[int] = None) -> ResponseReturnValue:
     form = NewMirrorListForm()
-    form.provider.choices = MirrorList.providers_supported.items()
-    form.format.choices = MirrorList.formats_supported.items()
-    form.encoding.choices = MirrorList.encodings_supported.items()
+    form.provider.choices = list(MirrorList.providers_supported.items())
+    form.format.choices = list(MirrorList.formats_supported.items())
+    form.encoding.choices = list(MirrorList.encodings_supported.items())
     if form.validate_on_submit():
         list_ = MirrorList()
         list_.provider = form.provider.data