diff --git a/environment.yml b/environment.yml
index b99b856187fb6..1ac190830c132 100644
--- a/environment.yml
+++ b/environment.yml
@@ -31,7 +31,7 @@ dependencies:
   # documentation
   - gitpython  # obtain contributors from git for whatsnew
   - gitdb
-  - sphinx
+  - sphinx=3.3.1
 
   # documentation (jupyter notebooks)
   - nbconvert>=5.4.1
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 17ca6b8401501..137c0db5f4408 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -17,7 +17,7 @@ pycodestyle
 pyupgrade
 gitpython
 gitdb
-sphinx
+sphinx==3.3.1
 nbconvert>=5.4.1
 nbsphinx
 pandoc