diff --git a/readthedocs.yml b/readthedocs.yml
index 6eae4b1868a498dcafa8e428d54ed97bd729c4ec..368b2c26721595ac5eaa2a180c5857585fe49117 100644
--- a/readthedocs.yml
+++ b/readthedocs.yml
@@ -17,7 +17,7 @@ formats:
 
 # Optionally set the version of Python and requirements required to build your docs
 python:
-  version: 3.8, 3.9
+  version: 3.8
   install:
     - requirements: doc/requirements.txt
     - method: pip