diff --git a/resources/user_resource.inc b/resources/user_resource.inc
index e7eead4..a68735b 100644
--- a/resources/user_resource.inc
+++ b/resources/user_resource.inc
@@ -349,7 +349,10 @@ function _user_resource_update($uid, $account) {
  */
 function _user_resource_delete($uid) {
   $account = user_load($uid);
-  if (empty($account)) {
+  if ($uid == 1) {
+    return services_error(t('The admin user cannot be deleted.'), 406);
+  }
+  elseif (empty($account)) {
     return services_error(t('There is no user with ID @uid.', array('@uid' => $uid)), 404);
   }
   user_delete($uid);
diff --git a/tests/functional/ServicesResourceUserTests.test b/tests/functional/ServicesResourceUserTests.test
index 6bae2f7..189e1d9 100644
--- a/tests/functional/ServicesResourceUserTests.test
+++ b/tests/functional/ServicesResourceUserTests.test
@@ -253,6 +253,23 @@ class ServicesResourceUsertests extends ServicesWebtestCase {
   }
 
   /**
+   * Test delete system user method.
+   */
+  function testDeleteSystemUser() {
+    // Delete user 0.
+    $response = $this->servicesDelete($this->endpoint->path . '/user/0');
+
+    $this->assertTrue(strpos($response['code'], '404') !== FALSE,
+      'Anonymous user was not deleted.', 'UserResource: Delete');
+
+    // Delete user 1.
+    $response = $this->servicesDelete($this->endpoint->path . '/user/1');
+
+    $this->assertTrue(strpos($response['status'], 'The admin user cannot be deleted.') !== FALSE,
+      'Admin user was not deleted.', 'UserResource: Delete');
+  }
+
+  /**
    * Test index method.
    *
    * Create several users list them. List one user by name.