diff --git a/django/contrib/admin/templates/widget/m2m_searchinput.html b/django/contrib/admin/templates/widget/m2m_searchinput.html
index 7f735328a1..145731a970 100644
--- a/django/contrib/admin/templates/widget/m2m_searchinput.html
+++ b/django/contrib/admin/templates/widget/m2m_searchinput.html
@@ -1,12 +1,9 @@
 {% load i18n %}
-
 <a href="{{ related_url }}{{ url }}" class="related-lookup" id="lookup_id_{{ name }}" onclick="return showRelatedObjectLookupPopup(this);">
   <img src="{{ admin_media_prefix }}img/admin/selector-search.gif" width="16" height="16" alt="{% trans "Lookup" %}" />
 </a>
 <script type="text/javascript">
 $(document).ready(function() {
-    // Show lookup input
-    
     $('#id_{{ name }}').tokenInput("{{ search_path }}", {
         noResultsText: "No results found.",
         searchingText: "Searching..."
diff --git a/django/contrib/admin/widgets.py b/django/contrib/admin/widgets.py
index 9c98880329..dc16215c9c 100644
--- a/django/contrib/admin/widgets.py
+++ b/django/contrib/admin/widgets.py
@@ -246,8 +246,12 @@ class ManyToManyRawIdWidget(ForeignKeyRawIdWidget):
 
     def value_from_datadict(self, data, files, name):
         value = data.get(name, None)
+        
+        if value and value[-1] == ',':
+            value = value[0:-1] # truncate trailing comma
+        
         if value and ',' in value:
-            return data[name].split(',')
+            return value.split(',')
         if value:
             return [value]
         return None