diff --git a/setup.py b/setup.py
index fd2919735..a9ab342ba 100644
--- a/setup.py
+++ b/setup.py
@@ -93,7 +93,7 @@ setup(
         ],
         'dev': [
             "flake8>=2.6.2, <3.1",
-            "mypy-lang>=0.4.5, <4.6",
+            "mypy-lang>=0.4.5, <0.5",
             "rstcheck>=2.2, <3.0",
             "tox>=2.3, <3",
             "mock>=2.0, <2.1",