diff --git a/wagtail/wagtailadmin/templates/wagtailadmin/shared/field.html b/wagtail/wagtailadmin/templates/wagtailadmin/shared/field.html
index 9113e1b6b..7c36be5d5 100644
--- a/wagtail/wagtailadmin/templates/wagtailadmin/shared/field.html
+++ b/wagtail/wagtailadmin/templates/wagtailadmin/shared/field.html
@@ -1,8 +1,8 @@
 {% load wagtailadmin_tags %}
-<div class="field {{ field.field_classnames }} {{ field|fieldtype }} {{ field_classes }}">
+<div class="field {{ field|fieldtype }} {{ field_classes }}">
     {{ field.label_tag }}
     <div class="field-content">
-        <div class="input {{ field.input_classnames }} {{ input_classes }} ">
+        <div class="input {{ input_classes }} ">
             {% block form_field %}
                 {{ field }}
             {% endblock %}