diff --git a/includes/file.inc b/includes/file.inc
index 1278d39d4799704700a84842c573c1b06e2e5d96..bc8ae79d325d54108ecd638521b4e20b67c6d408 100644
--- a/includes/file.inc
+++ b/includes/file.inc
@@ -605,7 +605,8 @@ function file_save(stdClass $file) {
  *
  * @return
  *   A nested array with usage data. The first level is keyed by module name,
- *   the second by object type, the third has 'id' and 'count' keys.
+ *   the second by object type and the third by the object id. The value
+ *   of the third level contains the usage count.
  *
  * @see file_usage_add()
  * @see file_usage_delete()
@@ -618,7 +619,7 @@ function file_usage_list(stdClass $file) {
     ->execute();
   $references = array();
   foreach ($result as $usage) {
-    $references[$usage->module][$usage->type] = array('id' => $usage->id, 'count' => $usage->count);
+    $references[$usage->module][$usage->type][$usage->id] = $usage->count;
   }
   return $references;
 }
diff --git a/modules/simpletest/tests/file.test b/modules/simpletest/tests/file.test
index 9dbe5464fc1e8b754daeabe24fbcaa8cdb46f344..db4097c44a0b38d5124f38540fcf294a9404cb94 100644
--- a/modules/simpletest/tests/file.test
+++ b/modules/simpletest/tests/file.test
@@ -1563,7 +1563,7 @@ class FileDeleteTest extends FileHookTestCase {
     file_usage_delete($file, 'testing', 'test', 1);
     file_delete($file);
     $usage = file_usage_list($file);
-    $this->assertEqual($usage['testing']['test'], array('id' => 1, 'count' => 1), t('Test file is still in use.'));
+    $this->assertEqual($usage['testing']['test'], array(1 => 1), t('Test file is still in use.'));
     $this->assertTrue(file_exists($file->uri), t('File still exists on the disk.'));
     $this->assertTrue(file_load($file->fid), t('File still exists in the database.'));
 
@@ -2066,10 +2066,10 @@ class FileUsageTest extends FileTestCase {
     $usage = file_usage_list($file);
 
     $this->assertEqual(count($usage['testing']), 2, t('Returned the correct number of items.'));
-    $this->assertEqual($usage['testing']['foo']['id'], 1, t('Returned the correct id.'));
-    $this->assertEqual($usage['testing']['bar']['id'], 2, t('Returned the correct id.'));
-    $this->assertEqual($usage['testing']['foo']['count'], 1, t('Returned the correct count.'));
-    $this->assertEqual($usage['testing']['bar']['count'], 2, t('Returned the correct count.'));
+    $this->assertTrue(isset($usage['testing']['foo'][1]), t('Returned the correct id.'));
+    $this->assertTrue(isset($usage['testing']['bar'][2]), t('Returned the correct id.'));
+    $this->assertEqual($usage['testing']['foo'][1], 1, t('Returned the correct count.'));
+    $this->assertEqual($usage['testing']['bar'][2], 2, t('Returned the correct count.'));
   }
 
   /**