diff --git a/.readthedocs.yml b/.readthedocs.yml
index d2f81d1..312c80a 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -5,6 +5,12 @@
 # Required
 version: 2
 
+# Set the version of Python and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "mambaforge-4.10"
+
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
   configuration: docs/conf.py
@@ -14,7 +20,8 @@ sphinx:
 #  configuration: mkdocs.yml
 
 # Optionally build your docs in additional formats such as PDF and ePub
-formats: all
+formats:
+  - htmlzip
 
 # Optionally set the version of Python and requirements required to build your docs
 conda:
diff --git a/docs/index.rst b/docs/index.rst
index 4275ed9..261a4be 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -37,6 +37,8 @@ The tools include:
     auto-scaling options, rounding to integer zoom factors to avoid
     resampling artifacts, and useful labeling (dimensions and gray-range).
 
+**NOTE**: If you are only interested in the complex steerable pyramid, we have a pytorch implementation in the `plenoptic <https://plenoptic.readthedocs.io/en/>`_ package; the implementation in plenoptic is differentiable.
+
 .. include:: quickstart.rst
 
 Pyramid resources