diff --git a/requirements/test.txt b/requirements/test.txt
index b892e633..6c70a726 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -61,7 +61,7 @@ pyyaml==5.1               # via -r test.in
 requests==2.23.0          # via sphinx
 snowballstemmer==2.0.0    # via pydocstyle, sphinx
 sortedcontainers==2.1.0   # via hypothesis
-sphinx==1.8.2             # via -r test.in
+sphinx==4.0.2             # via -r test.in
 sphinxcontrib-websupport==1.2.1  # via sphinx
 tenacity==5.0.2           # via -r test.in
 testtools==2.4.0          # via fixtures