diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 7bfe57b..8084831 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -1145,7 +1145,13 @@ function system_system_info_alter(&$info, Extension $file, $type) {
  */
 function system_default_region($theme) {
   $regions = array_keys(system_region_list($theme, REGIONS_VISIBLE));
+  $info = system_get_info('theme', $theme);
+  if (isset($info['block_default_region']) && in_array($info['block_default_region'], $regions)) {
+      return $info['block_default_region'];
+    }
+  else {
   return isset($regions[0]) ? $regions[0] : '';
+  }
 }
 
 /**