diff --git a/modules/block/block.module b/modules/block/block.module
index b534113ad8a..b1674f152f7 100644
--- a/modules/block/block.module
+++ b/modules/block/block.module
@@ -869,13 +869,4 @@ function block_form_system_performance_settings_alter(&$form, &$form_state) {
     '#description' => $disabled ? t('Block caching is inactive because you have enabled modules defining content access restrictions.') : NULL,
     '#weight' => -1,
   );
-
-  // Check if the "Who's online" block is enabled.
-  $online_block_enabled = db_query_range("SELECT 1 FROM {block} b WHERE module = 'user' AND delta = 'online' AND status = 1", 0, 1)->fetchField();
-
-  // If the "Who's online" block is enabled, append some descriptive text to
-  // the end of the form description.
-  if ($online_block_enabled) {
-    $form['page_cache']['cache']['#description'] .=  '<p>' . t('When caching is enabled, anonymous user sessions are only saved to the database when needed, so the "Who\'s online" block does not display the number of anonymous users.') . '</p>';
-  }
 }
diff --git a/modules/user/user.module b/modules/user/user.module
index 1cf567bb1dc..3a0dded2a6b 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -1138,7 +1138,6 @@ function user_block_configure($delta = '') {
       $period = drupal_map_assoc(array(30, 60, 120, 180, 300, 600, 900, 1800, 2700, 3600, 5400, 7200, 10800, 21600, 43200, 86400), 'format_interval');
       $form['user_block_seconds_online'] = array('#type' => 'select', '#title' => t('User activity'), '#default_value' => variable_get('user_block_seconds_online', 900), '#options' => $period, '#description' => t('A user is considered online for this long after they have last viewed a page.'));
       $form['user_block_max_list_count'] = array('#type' => 'select', '#title' => t('User list length'), '#default_value' => variable_get('user_block_max_list_count', 10), '#options' => drupal_map_assoc(array(0, 5, 10, 15, 20, 25, 30, 40, 50, 75, 100)), '#description' => t('Maximum number of currently online users to display.'));
-      $form['user_block_cache'] = array('#markup' => '<p>If page caching is disabled, the block shows the number of anonymous and authenticated users, respectively. If page caching is enabled, only the number of authenticated users is displayed.</p>');
       return $form;
   }
 }
@@ -1199,27 +1198,13 @@ function user_block_view($delta = '') {
         // rather than u.access because it is much faster.
         $authenticated_count = db_query("SELECT COUNT(DISTINCT s.uid) FROM {sessions} s WHERE s.timestamp >= :timestamp AND s.uid > 0", array(':timestamp' => $interval))->fetchField();
 
-        // When page caching is enabled, sessions are only created for
-        // anonymous users when needed.
-        if (variable_get('cache', CACHE_DISABLED) == CACHE_DISABLED) {
-          $anonymous_count = drupal_session_count($interval);
-          // Format the output with proper grammar.
-          if ($anonymous_count == 1 && $authenticated_count == 1) {
-            $output = t('There is currently %members and %visitors online.', array('%members' => format_plural($authenticated_count, '1 user', '@count users'), '%visitors' => format_plural($anonymous_count, '1 guest', '@count guests')));
-          }
-          else {
-            $output = t('There are currently %members and %visitors online.', array('%members' => format_plural($authenticated_count, '1 user', '@count users'), '%visitors' => format_plural($anonymous_count, '1 guest', '@count guests')));
-          }
-        }
-        else {
-          $output = format_plural($authenticated_count, 'There is currently 1 user online.', 'There are currently @count users online.');
-        }
+        $output = format_plural($authenticated_count, 'There is currently 1 user online.', 'There are currently @count users online.');
 
         // Display a list of currently online users.
         $max_users = variable_get('user_block_max_list_count', 10);
         if ($authenticated_count && $max_users) {
           $items = db_query_range('SELECT u.uid, u.name, MAX(s.timestamp) AS max_timestamp FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.timestamp >= :interval AND s.uid > 0 GROUP BY u.uid, u.name ORDER BY max_timestamp DESC', 0, $max_users, array(':interval' => $interval))->fetchAll();
-          $output .= theme('user_list', array('users' => $items, 'titles' => t('Online users')));
+          $output .= theme('user_list', array('users' => $items));
         }
 
         $block['subject'] = t('Who\'s online');
diff --git a/modules/user/user.test b/modules/user/user.test
index 186a45fedbd..352aa7a9607 100644
--- a/modules/user/user.test
+++ b/modules/user/user.test
@@ -1169,7 +1169,7 @@ class UserBlocksUnitTests extends DrupalWebTestCase {
     // Test block output.
     $block = user_block_view('online');
     $this->drupalSetContent($block['content']);
-    $this->assertRaw(t('%members and %visitors', array('%members' => '2 users', '%visitors' => '2 guests')), t('Correct number of online users (2 users and 2 guests).'));
+    $this->assertRaw(t('2 users'), t('Correct number of online users (2 users).'));
     $this->assertText($user1->name, t('Active user 1 found in online list.'));
     $this->assertText($user2->name, t('Active user 2 found in online list.'));
     $this->assertNoText($user3->name, t("Inactive user not found in online list."));