diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index f784b3f4b2f434138198a2072d1cb7398dc6a2a9..d2bda7f33db721b441d9413f3bf7dbff772a2e04 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -1006,19 +1006,6 @@ function system_rebuild_module_data() {
   return $modules_cache;
 }
 
-/**
- * Rebuild, save, and return data about all currently available themes.
- *
- * @return \Drupal\Core\Extension\Extension[]
- *   Array of all available themes and their data.
- *
- * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
- *   Use \Drupal::service('theme_handler')->rebuildThemeData().
- */
-function system_rebuild_theme_data() {
-  return \Drupal::service('theme_handler')->rebuildThemeData();
-}
-
 /**
  * Returns an array of default theme features.
  */