diff --git a/ci/requirements_all.txt b/ci/requirements_all.txt
index e9f49ed879c86..de37ec4d20be4 100644
--- a/ci/requirements_all.txt
+++ b/ci/requirements_all.txt
@@ -2,7 +2,7 @@ pytest
 pytest-cov
 pytest-xdist
 flake8
-sphinx
+sphinx=1.5*
 nbsphinx
 ipython
 python-dateutil