diff --git a/doc/conf.py b/doc/conf.py
index 6e5747186e..128002b1ed 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -140,10 +140,6 @@
 ]
 
 
-on_rtd = os.environ.get("READTHEDOCS") == "True"
-if on_rtd:
-    extensions.append("readthedocs_ext.readthedocs")
-
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]