diff --git a/requirements-dev.txt b/requirements-dev.txt
index a7ebe606f..facae20d8 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,6 +1,6 @@
 -r requirements.txt
 m2r>=0.2.0
 mypy>=0.600
-sphinx>=2.0.0
+sphinx>=2.0.0,<3.0.0
 pytest>=4.0.0
 pytest-cov>=2.6.0