diff --git a/environment.yml b/environment.yml
index aeca7c38..e9b832b4 100644
--- a/environment.yml
+++ b/environment.yml
@@ -13,6 +13,7 @@ dependencies:
   - sphinx==1.8.3
   - sphinx_rtd_theme==0.4.2
   - recommonmark==0.5.0
+  - requests-async==0.4.0
   - sphinxcontrib-asyncio>=0.2.0
   - docutils==0.14
   - pygments==2.3.1