diff --git a/aldryn_forms/admin/views.py b/aldryn_forms/admin/views.py
index 673bca65..5206aa87 100644
--- a/aldryn_forms/admin/views.py
+++ b/aldryn_forms/admin/views.py
@@ -95,13 +95,7 @@ def done(self, form_list, **kwargs):
 
         content_type = self.get_content_type()
 
-        response_kwargs = {}
-
-        if int(get_version().split('.')[1]) > 6:
-            response_kwargs['content_type'] = content_type
-        else:
-            # Django <= 1.6 compatibility
-            response_kwargs['mimetype'] = content_type
+        response_kwargs = {'content_type': content_type}
 
         response = HttpResponse(dataset.xls, **response_kwargs)
         response['Content-Disposition'] = 'attachment; filename=%s' % filename
diff --git a/aldryn_forms/cms_plugins.py b/aldryn_forms/cms_plugins.py
index 01813da6..0552a8fa 100644
--- a/aldryn_forms/cms_plugins.py
+++ b/aldryn_forms/cms_plugins.py
@@ -285,7 +285,7 @@ class Field(FormElement):
 
     def serialize_value(self, instance, value, is_confirmation=False):
         if isinstance(value, query.QuerySet):
-            value = u', '.join(map(text_type, value))
+            value = ', '.join(map(text_type, value))
         elif value is None:
             value = '-'
         return text_type(value)
diff --git a/aldryn_forms/contrib/email_notifications/cms_plugins.py b/aldryn_forms/contrib/email_notifications/cms_plugins.py
index 519308ca..a55db4b2 100644
--- a/aldryn_forms/contrib/email_notifications/cms_plugins.py
+++ b/aldryn_forms/contrib/email_notifications/cms_plugins.py
@@ -4,6 +4,7 @@
 
 from django.contrib import admin
 from django.core.mail import get_connection
+from django.utils.html import mark_safe
 from django.utils.translation import ugettext_lazy as _
 
 from cms.plugin_pool import plugin_pool
@@ -104,14 +105,14 @@ def text_variables(self, obj):
 
         for category, choices in choices_by_category:
             # <li>field_1</li><li>field_2</li>
-            fields_li = u''.join((u'<li>{0} | {1}</li>'.format(*var) for var in choices))
+            fields_li = ''.join(('<li>{0} | {1}</li>'.format(*var) for var in choices))
 
             if fields_li:
-                li_item = u'<li>{0}</li><ul>{1}</ul>'.format(category, fields_li)
+                li_item = '<li>{0}</li><ul>{1}</ul>'.format(category, fields_li)
                 li_items.append(li_item)
-        unordered_list = u'<ul>{0}</ul>'.format(u''.join(li_items))
-        help_text = u'<p class="help">{0}</p>'.format(self.text_variables_help_text)
-        return unordered_list + u'\n' + help_text
+        unordered_list = '<ul>{0}</ul>'.format(''.join(li_items))
+        help_text = '<p class="help">{0}</p>'.format(self.text_variables_help_text)
+        return mark_safe(unordered_list + '\n' + help_text)
     text_variables.allow_tags = True
     text_variables.short_description = _('available text variables')
 
diff --git a/aldryn_forms/contrib/email_notifications/models.py b/aldryn_forms/contrib/email_notifications/models.py
index 39718f36..2fa4d1ca 100644
--- a/aldryn_forms/contrib/email_notifications/models.py
+++ b/aldryn_forms/contrib/email_notifications/models.py
@@ -118,7 +118,7 @@ class Meta:
     def __str__(self):
         to_name = self.get_recipient_name()
         to_email = self.get_recipient_email()
-        return u'{0} ({1})'.format(to_name, to_email)
+        return '{0} ({1})'.format(to_name, to_email)
 
     def clean(self):
         recipient_email = self.get_recipient_email()
diff --git a/aldryn_forms/forms.py b/aldryn_forms/forms.py
index 08e0413b..b2da6451 100644
--- a/aldryn_forms/forms.py
+++ b/aldryn_forms/forms.py
@@ -219,7 +219,7 @@ def clean(self):
         min_value = self.cleaned_data.get('min_value')
         max_value = self.cleaned_data.get('max_value')
         if min_value and max_value and min_value > max_value:
-            self.append_to_errors('min_value', _(u'Min value can not be greater than max value.'))
+            self.append_to_errors('min_value', _('Min value can not be greater than max value.'))
         return self.cleaned_data
 
 
@@ -228,11 +228,11 @@ class TextFieldForm(MinMaxValueForm):
     def __init__(self, *args, **kwargs):
         super(TextFieldForm, self).__init__(*args, **kwargs)
 
-        self.fields['min_value'].label = _(u'Min length')
-        self.fields['min_value'].help_text = _(u'Required number of characters to type.')
+        self.fields['min_value'].label = _('Min length')
+        self.fields['min_value'].help_text = _('Required number of characters to type.')
 
-        self.fields['max_value'].label = _(u'Max length')
-        self.fields['max_value'].help_text = _(u'Maximum number of characters to type.')
+        self.fields['max_value'].label = _('Max length')
+        self.fields['max_value'].help_text = _('Maximum number of characters to type.')
         self.fields['max_value'].required = False
 
     class Meta:
@@ -309,11 +309,11 @@ class MultipleSelectFieldForm(MinMaxValueForm):
     def __init__(self, *args, **kwargs):
         super(MultipleSelectFieldForm, self).__init__(*args, **kwargs)
 
-        self.fields['min_value'].label = _(u'Min choices')
-        self.fields['min_value'].help_text = _(u'Required amount of elements to chose.')
+        self.fields['min_value'].label = _('Min choices')
+        self.fields['min_value'].help_text = _('Required amount of elements to chose.')
 
-        self.fields['max_value'].label = _(u'Max choices')
-        self.fields['max_value'].help_text = _(u'Maximum amount of elements to chose.')
+        self.fields['max_value'].label = _('Max choices')
+        self.fields['max_value'].help_text = _('Maximum amount of elements to chose.')
 
     class Meta:
         # 'required' and 'required_message' depend on min_value field validator
diff --git a/aldryn_forms/models.py b/aldryn_forms/models.py
index 96dd1faf..15d1ab3d 100644
--- a/aldryn_forms/models.py
+++ b/aldryn_forms/models.py
@@ -78,10 +78,10 @@ def field_id(self):
         field_label = self.label.strip()
 
         if field_label:
-            field_as_string = u'{}-{}'.format(field_label, self.field_type)
+            field_as_string = '{}-{}'.format(field_label, self.field_type)
         else:
             field_as_string = self.name
-        field_id = u'{}:{}'.format(field_as_string, self.field_occurrence)
+        field_id = '{}:{}'.format(field_as_string, self.field_occurrence)
         return field_id
 
     @property
@@ -261,10 +261,10 @@ def get_form_fields(self):
             if field_plugin.name:
                 field_name = field_plugin.name
             else:
-                field_name = u'{0}_{1}'.format(field_type, field_type_occurrence)
+                field_name = '{0}_{1}'.format(field_type, field_type_occurrence)
 
             if field_label:
-                field_id = u'{0}_{1}'.format(field_type, field_label)
+                field_id = '{0}_{1}'.format(field_type, field_label)
             else:
                 field_id = field_name
 
@@ -591,7 +591,7 @@ def _form_data_hook(self, data, occurrences):
 
         if field_label:
             field_type = data['name'].rpartition('_')[0]
-            field_id = u'{}_{}'.format(field_type, field_label)
+            field_id = '{}_{}'.format(field_type, field_label)
         else:
             field_id = data['name']
 
diff --git a/aldryn_forms/sizefield/models.py b/aldryn_forms/sizefield/models.py
index d30d6cb1..c33496d4 100644
--- a/aldryn_forms/sizefield/models.py
+++ b/aldryn_forms/sizefield/models.py
@@ -8,7 +8,7 @@
 
 class FileSizeField(models.BigIntegerField):
     default_error_messages = {
-        'invalid': _(u'Incorrect file size format.'),
+        'invalid': _('Incorrect file size format.'),
     }
 
     def formfield(self, **kwargs):
diff --git a/setup.py b/setup.py
index aa10a311..cc3317d4 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@
     'djangocms-text-ckeditor',
     'djangocms-attributes-field>=1.0.0',
     'django-tablib',
-    'tablib',
+    'tablib==0.13.0',
     'pillow',
     'django-filer',
     'django-sizefield',