diff --git a/ci/requirements-3.6_DOC.run b/ci/requirements-3.6_DOC.run
index df8087f62ef16..f87760b507357 100644
--- a/ci/requirements-3.6_DOC.run
+++ b/ci/requirements-3.6_DOC.run
@@ -1,7 +1,7 @@
 ipython
 ipykernel
 ipywidgets
-sphinx
+sphinx=1.5*
 nbconvert
 nbformat
 notebook