diff --git a/core/modules/history/history.install b/core/modules/history/history.install
index dcfd871..0117e49 100644
--- a/core/modules/history/history.install
+++ b/core/modules/history/history.install
@@ -13,17 +13,24 @@ function history_schema() {
     'description' => 'A record of which {users} have read which {node}s.',
     'fields' => array(
       'uid' => array(
-        'description' => 'The {users}.uid that read the {node} nid.',
+        'description' => 'The {users}.uid that read the entity_id.',
         'type' => 'int',
         'not null' => TRUE,
         'default' => 0,
       ),
-      'nid' => array(
-        'description' => 'The {node}.nid that was read.',
+      'entity_id' => array(
+        'description' => 'The entity_id that was read.',
         'type' => 'int',
         'not null' => TRUE,
         'default' => 0,
       ),
+      'entity_type' => array(
+        'type' => 'varchar',
+        'not null' => TRUE,
+        'default' => 'node',
+        'length' => 255,
+        'description' => 'The entity_type of the entity was read.',
+      ),
       'timestamp' => array(
         'description' => 'The Unix timestamp at which the read occurred.',
         'type' => 'int',
@@ -31,11 +38,51 @@ function history_schema() {
         'default' => 0,
       ),
     ),
-    'primary key' => array('uid', 'nid'),
+    'primary key' => array(
+      'uid',
+      'entity_id',
+      array('entity_type', 32),
+    ),
     'indexes' => array(
-      'nid' => array('nid'),
+      'history_entity' => array(
+        'entity_id',
+        array('entity_type', 32),
+      ),
     ),
   );
 
   return $schema;
 }
+
+/**
+ * Upgrades {history} to be used for any entity type.
+ */
+function history_update_8000() {
+  // Drop all keys to properly rename constraints.
+  db_drop_primary_key('history');
+  db_drop_index('history', 'nid');
+  // Add new column.
+  db_add_field('history', 'entity_type', array(
+    'type' => 'varchar',
+    'not null' => TRUE,
+    'default' => 'node',
+    'length' => 255,
+    'description' => 'The entity_type of the entity was read.',
+  ));
+  db_change_field('history', 'nid', 'entity_id', array(
+    'description' => 'The entity_id that was read.',
+    'type' => 'int',
+    'not null' => TRUE,
+    'default' => 0,
+  ));
+  // Create new indexes.
+  db_add_primary_key('history', array(
+    'uid',
+    'entity_id',
+    array('entity_type', 32),
+  ));
+  db_add_index('history', 'history_entity', array(
+    'entity_id',
+    array('entity_type', 32),
+  ));
+}
diff --git a/core/modules/history/history.module b/core/modules/history/history.module
index 45027fe..8246dd4 100644
--- a/core/modules/history/history.module
+++ b/core/modules/history/history.module
@@ -22,34 +22,43 @@
 /**
  * Retrieves the timestamp for the current user's last view of a specified node.
  *
- * @param int $nid
- *   A node ID.
+ * @param int $entity_id
+ *   The entity ID.
+ * @param string $entity_type
+ *   The entity type. Defaults to "node".
  *
  * @return int
  *   If a node has been previously viewed by the user, the timestamp in seconds
  *   of when the last view occurred; otherwise, zero.
  */
-function history_read($nid) {
+function history_read($entity_id, $entity_type = 'node') {
   global $user;
   $history = &drupal_static(__FUNCTION__, array());
 
-  if (!isset($history[$nid])) {
-    $history[$nid] = db_query("SELECT timestamp FROM {history} WHERE uid = :uid AND nid = :nid", array(':uid' => $user->uid, ':nid' => $nid))->fetchObject();
+  if (!isset($history[$entity_id])) {
+    $history[$entity_id] = db_query("SELECT timestamp FROM {history} WHERE uid = :uid AND entity_id = :entity_id AND entity_type = :entity_type", array(
+      ':uid' => $user->uid,
+      ':entity_id' => $entity_id,
+      ':entity_type' => $entity_type,
+    ))
+      ->fetchObject();
   }
 
-  return (isset($history[$nid]->timestamp) ? $history[$nid]->timestamp : 0);
+  return (isset($history[$entity_id]->timestamp) ? $history[$entity_id]->timestamp : 0);
 }
 
 /**
  * Updates 'last viewed' timestamp of the specified entity for the current user.
  *
- * @param $nid
- *   The node ID that has been read.
+ * @param $entity_id
+ *   The entity ID that has been read.
+ * @param $entity_type
+ *   The entity type. Defaults to "node".
  * @param $account
  *   (optional) The user account to update the history for. Defaults to the
  *   current user.
  */
-function history_write($nid, $account = NULL) {
+function history_write($entity_id, $entity_type = 'node', $account = NULL) {
   global $user;
 
   if (!isset($account)) {
@@ -60,7 +69,8 @@ function history_write($nid, $account = NULL) {
     db_merge('history')
       ->key(array(
         'uid' => $account->uid,
-        'nid' => $nid,
+        'entity_id' => $entity_id,
+        'entity_type' => $entity_type,
       ))
       ->fields(array('timestamp' => REQUEST_TIME))
       ->execute();
@@ -81,7 +91,8 @@ function history_cron() {
  */
 function history_node_delete(Node $node) {
   db_delete('history')
-    ->condition('nid', $node->nid)
+    ->condition('entity_id', $node->nid)
+    ->condition('entity_type', 'node')
     ->execute();
 }
 
@@ -93,6 +104,7 @@ function history_user_cancel($edit, $account, $method) {
     case 'user_cancel_reassign':
       db_delete('history')
         ->condition('uid', $account->uid)
+        ->condition('entity_type', 'user')
         ->execute();
       break;
   }
@@ -104,5 +116,6 @@ function history_user_cancel($edit, $account, $method) {
 function history_user_delete($account) {
   db_delete('history')
     ->condition('uid', $account->uid)
+    ->condition('entity_type', 'user')
     ->execute();
 }
diff --git a/core/modules/history/history.views.inc b/core/modules/history/history.views.inc
index ed36820..9bf753b 100644
--- a/core/modules/history/history.views.inc
+++ b/core/modules/history/history.views.inc
@@ -24,8 +24,9 @@ function history_views_data() {
     'node' => array(
       'table' => 'history',
       'left_field' => 'nid',
-      'field' => 'nid',
+      'field' => 'entity_id',
       'extra' => array(
+        array('field' => 'entity_type', 'value' => 'node'),
         array('field' => 'uid', 'value' => '***CURRENT_USER***', 'numeric' => TRUE),
       ),
     ),