diff --git a/pyproject.toml b/pyproject.toml
index 329728966..ecc336092 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,6 +40,11 @@ exclude = [
 module = "tests.*"
 ignore_errors = true
 
+[[tool.mypy.overrides]]
+# Telegram does not use implicit_optional = false in the current version.
+module = "telegram.*"
+implicit_optional = true
+
 [build-system]
 requires = ["setuptools >= 46.4.0", "wheel"]
 build-backend = "setuptools.build_meta"