diff --git a/src/__tests__/PhabricatorInfrastructureTestCase.php b/src/__tests__/PhabricatorInfrastructureTestCase.php
--- a/src/__tests__/PhabricatorInfrastructureTestCase.php
+++ b/src/__tests__/PhabricatorInfrastructureTestCase.php
@@ -1,7 +1,6 @@
 <?php
 
-final class PhabricatorInfrastructureTestCase
-  extends PhabricatorTestCase {
+final class PhabricatorInfrastructureTestCase extends PhabricatorTestCase {
 
   protected function getPhabricatorTestCaseConfiguration() {
     return array(
@@ -10,7 +9,7 @@
   }
 
   /**
-   * This is more of an acceptance test case instead of a unittest. It verifies
+   * This is more of an acceptance test case instead of a unit test. It verifies
    * that all symbols can be loaded correctly. It can catch problems like
    * missing methods in descendants of abstract base classes.
    */
@@ -19,6 +18,29 @@
     $this->assertTrue(true);
   }
 
+  /**
+   * This is more of an acceptance test case instead of a unit test. It verifies
+   * that all the library map is up-to-date.
+   */
+  public function testLibraryMap() {
+    $root = phutil_get_library_root('phabricator');
+
+    $new_library_map = id(new PhutilLibraryMapBuilder($root))
+      ->setQuiet(true)
+      ->setDryRun(true)
+      ->buildMap();
+
+    $bootloader = PhutilBootloader::getInstance();
+    $old_library_map = $bootloader->getLibraryMap('phabricator');
+    unset($old_library_map[PhutilLibraryMapBuilder::LIBRARY_MAP_VERSION_KEY]);
+
+    $this->assertEqual(
+      $new_library_map,
+      $old_library_map,
+      'The library map does not appear to be up-to-date. Try '.
+      'rebuilding the map with `arc liberate`.');
+  }
+
   public function testApplicationsInstalled() {
     $all = PhabricatorApplication::getAllApplications();
     $installed = PhabricatorApplication::getAllInstalledApplications();