diff --git a/CHANGELOG.md b/CHANGELOG.md
index f052a1ed..26062b39 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## 5.15.1.0 [unreleased]
 
 ### Added
+* [#99](https://github.com/stlehmann/PyQt5-stubs/pull/99) enable mypy's strict mode
 * [#92](https://github.com/stlehmann/PyQt5-stubs/pull/92) add `Sequence` methods and `.__setitem__()` to `sip.array`
 * [#94](https://github.com/stlehmann/PyQt5-stubs/pull/94) add several operators to `QIODevice.OpenMode` and `QIODevice.OpenModeFlag`
 * [#93](https://github.com/stlehmann/PyQt5-stubs/pull/93) test against 3.5, 3.6, 3.7, 3.8, and 3.9
diff --git a/setup.cfg b/setup.cfg
index a421b295..21edd450 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,4 +1,6 @@
 [mypy]
+incremental = False
+
+strict = True
+warn_unreachable = True
 ignore_missing_imports = False
-disallow_untyped_calls = True
-disallow_untyped_defs = True