diff --git a/app/forms.py b/app/forms.py
index 98624aa..784221b 100644
--- a/app/forms.py
+++ b/app/forms.py
@@ -12,7 +12,7 @@ class DeckForm(FlaskForm):
 class PasswordForm(FlaskForm):
     value = StringField("Password", validators=[DataRequired()])
     expires_at = DateTimeField("Expires At (Timezone: Europe/Berlin, optional)", format="%Y-%m-%dT%H:%M", validators=[Optional()])
-    decks = SelectMultipleField("Decks", validators=[DataRequired()])
+    decks = SelectMultipleField("Decks", coerce=int, validators=[DataRequired()])
     submit_password = SubmitField("Submit Password")