diff --git a/docs/environment.yml b/docs/environment.yml
index 9726d0868..1965ab5e5 100644
--- a/docs/environment.yml
+++ b/docs/environment.yml
@@ -8,5 +8,5 @@ dependencies:
 - jupyter_client
 - ipykernel
 - pip:
-  - sphinx>=1.3.6
+  - sphinx<1.4
   - nbsphinx