diff --git a/pyproject.toml b/pyproject.toml
index 992b84ec..9b362a19 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,6 +58,7 @@ profile = "black"
 [tool.mypy]
 python_version = 3.8
 warn_unused_configs = true
+disallow_incomplete_defs = true
 
 exclude = [
     'docs/*',