diff --git a/ennstatus/donate/forms.py b/ennstatus/donate/forms.py
--- a/ennstatus/donate/forms.py
+++ b/ennstatus/donate/forms.py
@@ -6,5 +6,7 @@ from wtforms.validators import DataRequi
 class DateForm(Form):
     year = SelectField('Year', validators=[DataRequired()])
     month = SelectField('Month',
-                        choices=[('{:02d}'.format(i), str(i)) for i in range(1, 13)],
+                        choices=[
+                            ('{:02d}'.format(i), str(i)) for i in range(1, 13)
+                        ],
                         validators=[DataRequired()])