diff -u b/core/includes/module.inc b/core/includes/module.inc
--- b/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -189,8 +189,14 @@
   $enabled_modules = config('system.module')->get();
   _system_list_warm('module', 'system', 'core/modules/system.module', TRUE);
   system_list_reset();
-  $module_data = system_rebuild_module_data(FALSE);
-  $theme_data = system_rebuild_theme_data(FALSE);
+  $module_file_list = state()->get('system.module_file_list');
+  $theme_data = state()->get('system.themes');
+  // As themes do not need to be installed to be used during installation the
+  // state entry for system.themes might not exist. This will be resolved by
+  // http://drupal.org/node/1067408.
+  if (empty($theme_data)) {
+    $theme_data = system_rebuild_theme_data(FALSE);
+  }
   $lists = array(
     'bootstrap' => array(),
     'module_enabled' => array(),
@@ -240,7 +246,7 @@
   foreach ($enabled_modules as $name => $weight) {
     // Build a list of all enabled modules.
     $lists['module_enabled'][$name] = $name;
-    $filename = $module_data[$name]->filename;
+    $filename = $module_file_list[$name];
     // Build a list of filenames so drupal_get_filename can use it.
     $lists['filepaths'][] = array(
       'type' => 'module',
diff -u b/core/modules/system/system.module b/core/modules/system/system.module
--- b/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -2811,6 +2811,7 @@
   // reference from system_list_reset() during the rebuild.
   if (!isset($modules_cache['data'])) {
     $modules = _system_rebuild_module_data();
+    $module_file_list = array();
     ksort($modules);
     // Add status, weight and schema.
     foreach ($modules as $module => $record) {
@@ -2819,6 +2820,7 @@
       $record->weight = 0;
       $record->status = 0;
       $record->schema_version = SCHEMA_UNINSTALLED;
+      $module_file_list[$module] = $record->filename;
     }
     // Enabled status and weights.
     foreach (config('system.module')->get() as $module => $weight) {
@@ -2831,6 +2833,9 @@
       system_list_reset();
     }
     $modules_cache['data'] = $modules;
+    // Store module filenames so that if can be retrieved during system_list()
+    // without a rebuild.
+    state()->set('system.module_file_list', $module_file_list);
   }
   // Running the info alter function is not possible before full bootstrap.
   if (!isset($modules_cache['info_alter']) && drupal_get_bootstrap_phase() >= DRUPAL_BOOTSTRAP_CODE) {
@@ -3006,6 +3011,9 @@
   if ($reset) {
     system_list_reset();
   }
+  // Store theme data so that if can be retrieved during system_list() without
+  // a rebuild.
+  state()->set('system.themes', $themes);
   return $themes;
 }