diff --git a/docs/conf.py b/docs/conf.py
index 141755f1bc..bfca7886d9 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -36,6 +36,7 @@
     "sphinx.ext.intersphinx",
     "sphinx.ext.napoleon",
     "sphinx.ext.viewcode",
+    "sphinx.ext.duration",
     "sphinxcontrib_trio",
     # "details",
     "exception_hierarchy",