diff --git a/mo/db.py b/mo/db.py
index e827ea09135eaffc62d33f1a6ca4590ec09d63c8..b76a4c1d89dad7c69191b4b3508d90410d98f0a0 100644
--- a/mo/db.py
+++ b/mo/db.py
@@ -208,8 +208,8 @@ class Round(Base):
     def task_statement_available(self) -> bool:
         # Zde jsme raději přepečliví...
         return (self.state != RoundState.preparing
-                and self.tasks_file is not None
-                and self.ct_tasks_start is not None
+                and self.tasks_file
+                and self.ct_tasks_start
                 and mo.now >= self.ct_tasks_start)
 
     def ct_can_submit(self) -> bool:
diff --git a/mo/web/org_round.py b/mo/web/org_round.py
index 1980e6a47be751307cd3be92f4bc14ef9cf4c927..86339bb25b1706325471734c78fb807ce21c1c8c 100644
--- a/mo/web/org_round.py
+++ b/mo/web/org_round.py
@@ -250,7 +250,7 @@ class RoundEditForm(FlaskForm):
     state = wtforms.SelectField("Stav kola", choices=db.RoundState.choices(), coerce=db.RoundState.coerce)
     # Only the desktop Firefox does not support datetime-local field nowadays,
     # other browsers does provide date and time picker UI :(
-    tasks_file = wtforms.StringField("Soubor se zadáním", description="Cesta k ručně uploadovanému souboru")
+    tasks_file = wtforms.StringField("Soubor se zadáním", description="Cesta k ručně uploadovanému souboru", filters=[lambda x: x or None])
     ct_tasks_start = DateTimeLocalField(
         "Čas zveřejnění úloh", validators=[validators.Optional()],
         description="Ve formátu 2020-01-01 00:00:00"