diff --git a/doc_build/rtd_env.yml b/doc_build/rtd_env.yml
index 3a148453..263dc0f5 100644
--- a/doc_build/rtd_env.yml
+++ b/doc_build/rtd_env.yml
@@ -14,4 +14,4 @@ dependencies:
     - nbsphinx
     - IPython
     - readthedocs-sphinx-search>=0.1.0
-    - git+https://github.com/LinkedEarth/Pyleoclim_util.git@Development
+    - git+https://github.com/LinkedEarth/Pyleoclim_util.git@master