diff --git a/modeltranslation/admin.py b/modeltranslation/admin.py
index 0281d2d..e852dc6 100644
--- a/modeltranslation/admin.py
+++ b/modeltranslation/admin.py
@@ -57,7 +57,7 @@ class TranslationBaseModelAdmin(BaseModelAdmin):
         else:
             orig_formfield = self.formfield_for_dbfield(orig_field, **kwargs)
             field.widget = deepcopy(orig_formfield.widget)
-            if orig_field.null and isinstance(field.widget, (forms.TextInput, forms.Textarea)):
+            if db_field.null and isinstance(field.widget, (forms.TextInput, forms.Textarea)):
                 field.widget = ClearableWidgetWrapper(field.widget)
             css_classes = field.widget.attrs.get('class', '').split(' ')
             css_classes.append('mt')
diff --git a/modeltranslation/fields.py b/modeltranslation/fields.py
index 838874a..cfad22d 100644
--- a/modeltranslation/fields.py
+++ b/modeltranslation/fields.py
@@ -177,7 +177,7 @@ class TranslationField(object):
         values to be preserved rather than saved as empty strings.
         """
         formfield = super(TranslationField, self).formfield(*args, **kwargs)
-        if self.translated_field.null:
+        if self.null:
             if isinstance(formfield, forms.CharField):
                 from modeltranslation.forms import NullableField
                 form_class = formfield.__class__