Index: field_permissions.module
===================================================================
--- field_permissions.module	(revision 17724)
+++ field_permissions.module	(working copy)
@@ -50,15 +50,17 @@
     'type' => MENU_DEFAULT_LOCAL_TASK,
     'weight' => -10,
   );
-  $items['admin/reports/fields/permissions'] = array(
-    'title' => 'Permissions',
-    'description' => 'Report and troubleshoot field permissions.',
-    'page callback' => 'field_permissions_overview',
-    'access arguments' => array('administer field permissions'),
-    'file' => 'field_permissions.admin.inc',
-    'type' => MENU_LOCAL_TASK,
-    'weight' => 0,
-  );
+  if (module_exists('field_ui')) {
+    $items['admin/reports/fields/permissions'] = array(
+      'title' => 'Permissions',
+      'description' => 'Report and troubleshoot field permissions.',
+      'page callback' => 'field_permissions_overview',
+      'access arguments' => array('administer field permissions'),
+      'file' => 'field_permissions.admin.inc',
+      'type' => MENU_LOCAL_TASK,
+      'weight' => 0,
+    );
+  }
   return $items;
 }