diff --git a/doc/source/conf.py b/doc/source/conf.py
index 40622c67f3a..7e43a3b1698 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -206,6 +206,7 @@ def reset_servers(gallery_conf, fname, when):
     #                         "set_plot_theme('document')"),
     "reset_modules_order": 'both',
     "reset_modules": (reset_servers,),
+    "parallel": 2,
 }