diff --git a/doc/conf.py b/doc/conf.py
index deb22096df2f..7c4be3d71457 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -141,6 +141,7 @@ def _check_dependencies():
     'within_subsection_order': gallery_order.subsectionorder,
     'remove_config_comments': True,
     'min_reported_time': 1,
+    'thumbnail_size': (160, 112),
     'compress_images': ('thumbnails', 'images'),
     'matplotlib_animations': True,
 }