diff --git a/plinth/templatetags/plinth_extras.py b/plinth/templatetags/plinth_extras.py
index 2ccef470b..80dea0203 100644
--- a/plinth/templatetags/plinth_extras.py
+++ b/plinth/templatetags/plinth_extras.py
@@ -25,10 +25,12 @@ def mark_active_menuitem(menu, path):
     """Mark the best-matching menu item with 'active'
 
     Input: a menu dict in the form of:
-    {'title': 'x',
-     'items': [{'url': 'a/b', 'text': 'myUrl'}, {'url': ...}]
+    {'title': 'foo menu',
+     'items': [{'url': '/path/to/choice1/', 'text': 'choice 1'}, {'url': ...}]
     }
 
+    URL paths are expected to end with a slash for matches to work properly.
+
     Output: The same dictionary; the best-matching URL dict gets the value
     'active': True. All other URL dicts get the value 'active': False.
 
@@ -41,8 +43,8 @@ def mark_active_menuitem(menu, path):
         urlitem['active'] = False
         if not path.startswith(str(urlitem['url'])):
             continue
-        match = os.path.commonprefix([urlitem['url'], path])
 
+        match = os.path.commonprefix([urlitem['url'], path])
         if len(match) > len(best_match):
             best_match = match
             best_match_item = urlitem
@@ -54,7 +56,7 @@ def mark_active_menuitem(menu, path):
 
 
 @register.inclusion_tag('subsubmenu.html', takes_context=True)
-def show_subsubmenu(context, menudata):
+def show_subsubmenu(context, menu):
     """Mark the active menu item and display the subsubmenu"""
-    menudata = mark_active_menuitem(menudata, context['request'].path)
-    return {'subsubmenu': menudata}
+    menu = mark_active_menuitem(menu, context['request'].path)
+    return {'subsubmenu': menu}
diff --git a/plinth/tests/test_templatetags.py b/plinth/tests/test_templatetags.py
index 2a2b55c56..c34a363c0 100644
--- a/plinth/tests/test_templatetags.py
+++ b/plinth/tests/test_templatetags.py
@@ -1,5 +1,3 @@
-#!/usr/bin/python3
-# -*- mode: python; mode: auto-fill; fill-column: 80 -*-
 #
 # This file is part of Plinth.
 #
@@ -22,48 +20,38 @@ import unittest
 from plinth.templatetags.plinth_extras import mark_active_menuitem
 
 
-class TestPrivileged(unittest.TestCase):
+class TestShowSubSubMenu(unittest.TestCase):
     """Verify that the highlighting of the subsubmenu is working correctly"""
-
-    def is_active_url(self, menu, url):
+    def assert_active_url(self, menu, url):
         """Verify that only the given url is set as 'active' in the menu"""
-        for urlitem in menu['items']:
-            if urlitem['url'] == url and not urlitem['active']:
-                return False
-            if urlitem['url'] != url and urlitem['active']:
-                return False
-        return True
+        for item in menu['items']:
+            if item['url'] == url:
+                self.assertTrue(item['active'])
+            else:
+                self.assertFalse(item['active'])
 
-    def verify_active_menuitems(self, menu):
+    def _verify_active_menuitems(self, menu):
         """Verify that one and only one menuitem is marked as active"""
-        return sum([x['active'] for x in menu['items']])==1
+        return sum([item['active'] for item in menu['items']]) == 1
 
     def test_highlighting(self):
         """Test detection of active subsubmenu items using request.path"""
         menu = {
-            "text": "blubb",
-            "items": [{'url': '/abc/123/abc/', 'text': 'abc'},
+            'text': 'blubb',
+            'items': [{'url': '/abc/123/abc/', 'text': 'abc'},
                       {'url': '/abc/123/', 'text': 'overview'},
                       {'url': '/abc/123/crunch/', 'text': 'crunch'},
                       {'url': '/abc/123/create/', 'text': 'create'}]
         }
 
-        menu = mark_active_menuitem(menu, '/abc/123/crunch/new/')
-        assert(self.is_active_url(menu, '/abc/123/crunch/'))
-        assert(self.verify_active_menuitems(menu))
+        tests = [['/abc/123/crunch/new/', '/abc/123/crunch/'],
+                 ['/abc/123/create/', '/abc/123/create/'],
+                 ['/abc/123/nolink/', '/abc/123/'],
+                 ['/abc/123/abx/', '/abc/123/'],
+                 ['/abc/123/ab/', '/abc/123/'],
+                 ['/abc/123/', '/abc/123/']]
 
-        menu = mark_active_menuitem(menu, '/abc/123/create/')
-        assert(self.is_active_url(menu, '/abc/123/create/'))
-        assert(self.verify_active_menuitems(menu))
-
-        menu = mark_active_menuitem(menu, '/abc/123/nolink/')
-        assert(self.is_active_url(menu, '/abc/123/'))
-        assert(self.verify_active_menuitems(menu))
-
-        menu = mark_active_menuitem(menu, '/abc/123/abx/')
-        assert(self.is_active_url(menu, '/abc/123/'))
-        assert(self.verify_active_menuitems(menu))
-
-        menu = mark_active_menuitem(menu, '/abc/123/')
-        assert(self.is_active_url(menu, '/abc/123/'))
-        assert(self.verify_active_menuitems(menu))
+        for check_path, expected_active_path in tests:
+            menu = mark_active_menuitem(menu, check_path)
+            self.assert_active_url(menu, expected_active_path)
+            self.assertTrue(self._verify_active_menuitems(menu))