diff --git a/mypy.ini b/mypy.ini
index 641e18c17..2cf00a8c8 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -15,6 +15,8 @@ disallow_untyped_defs = true
 disallow_incomplete_defs = true
 show_error_codes = false
 disable_error_code = empty-body
+force_uppercase_builtins = true
+force_union_syntax = true
 
 
 plugins =
diff --git a/setup.py b/setup.py
index 809c187d0..737001e57 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@ def find_stub_files(name: str) -> List[str]:
 ]
 
 extras_require = {
-    "compatible-mypy": ["mypy>=1.3.0,<1.5"],
+    "compatible-mypy": ["mypy>=1.4.0,<1.4"],
 }
 
 setup(