diff --git a/ihatemoney/forms.py b/ihatemoney/forms.py
index c818b75b..701e7c58 100644
--- a/ihatemoney/forms.py
+++ b/ihatemoney/forms.py
@@ -151,7 +151,7 @@ class BillForm(FlaskForm):
 class MemberForm(FlaskForm):
     name = StringField(_("Name"), validators=[Required()])
 
-    wieght_validators = [NumberRange(min=0.1, message=_("Weights should be positive"))]
+    weight_validators = [NumberRange(min=0.1, message=_("Weights should be positive"))]
     weight = CommaDecimalField(_("Weight"), default=1,
                                validators=weight_validators)
     submit = SubmitField(_("Add"))
diff --git a/ihatemoney/models.py b/ihatemoney/models.py
index c6ce23fb..1ba3f7ba 100644
--- a/ihatemoney/models.py
+++ b/ihatemoney/models.py
@@ -346,7 +346,10 @@ class Bill(db.Model):
         """Compute what each share has to pay"""
         if self.owers:
             # FIXME: SQL might dot that more efficiently
-            return self.amount / sum(i.weight for i in self.owers)
+            weights = sum(i.weight for i in self.owers)
+            if weights <= 0:
+                weights = 1
+            return self.amount / weights
         else:
             return 0