diff --git a/composer.json b/composer.json
index ec60b9c..09068a3 100644
--- a/composer.json
+++ b/composer.json
@@ -19,6 +19,7 @@
 		"jakub-onderka/php-parallel-lint": "^0.9.2",
 		"phing/phing": "^2.13.0",
 		"phpstan/phpstan-phpunit": "^0.9",
+		"phpstan/phpstan-strict-rules": "^0.9",
 		"phpunit/phpunit": "^6.4",
 		"satooshi/php-coveralls": "^1.0",
 		"slevomat/coding-standard": "^2.0"
diff --git a/phpstan.neon b/phpstan.neon
index b2b86dc..6cb3b5b 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,3 +1,4 @@
 includes:
 	- vendor/phpstan/phpstan-phpunit/extension.neon
 	- vendor/phpstan/phpstan-phpunit/rules.neon
+	- vendor/phpstan/phpstan-strict-rules/rules.neon