diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c888c95..d17992b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -28,4 +28,7 @@ jobs:
         run: composer install
 
       - name: Run tests
-        run: ./vendor/bin/phpunit
+        run: vendor/bin/phpunit
+
+      - name: Run tests
+        run: vendor/bin/phpstan
diff --git a/composer.json b/composer.json
index 73b97e8..5f36eaf 100644
--- a/composer.json
+++ b/composer.json
@@ -18,11 +18,15 @@
 		"php": "^7.2|^8.0"
 	},
 	"require-dev": {
+		"phpstan/phpstan": "^1.10",
 		"phpunit/phpunit": "~5|~9"
 	},
 	"autoload": {
 		"files": [
 			"src/streams.php"
 		]
+	},
+	"config": {
+		"sort-packages": true
 	}
 }
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..aeb0535
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,5 @@
+parameters:
+	level: 6
+	paths:
+		- src
+		- test