diff --git a/composer.json b/composer.json
index 0c80ab7..f9e81c6 100644
--- a/composer.json
+++ b/composer.json
@@ -20,11 +20,14 @@
     "check": [
       "@analyze",
       "@tests",
-      "@tests-spec"
+      "@tests-spec",
+      "@cs-check"
     ],
     "tests": "phpunit tests",
     "analyze": "phpstan analyse --level max",
-    "tests-spec": "phpspec run --no-interaction"
+    "tests-spec": "phpspec run --no-interaction",
+    "cs-check": "phpcs --parallel=50",
+    "cs-fix": "phpcbf"
   },
   "require-dev": {
     "phpspec/phpspec": "^6.2",
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
new file mode 100644
index 0000000..1c5e692
--- /dev/null
+++ b/phpcs.xml.dist
@@ -0,0 +1,21 @@
+<?xml version = "1.0"?>
+<ruleset name="PSR12 coding standard">
+    <!-- display progress -->
+    <arg value="p"/>
+    <arg name="colors"/>
+
+    <!-- inherit rules from: -->
+    <rule ref="PSR12">
+        <exclude name="Generic.Files.LineLength"/>
+    </rule>
+    <rule ref="Generic.Arrays.DisallowLongArraySyntax"/>
+    <rule ref="Squiz.WhiteSpace.SuperfluousWhitespace">
+        <properties>
+            <property name="ignoreBlankLines" value="false"/>
+        </properties>
+    </rule>
+
+    <!-- Paths to check -->
+    <file>src</file>
+    <file>tests</file>
+</ruleset>
\ No newline at end of file
diff --git a/src/Check/NumericRangeCheck.php b/src/Check/NumericRangeCheck.php
index 581ccee..ef3dc38 100644
--- a/src/Check/NumericRangeCheck.php
+++ b/src/Check/NumericRangeCheck.php
@@ -48,7 +48,7 @@ public function check(string $key, $value): ResultInterface
         $result = $this->child->check($key, $value);
 
         if (!$result->isValid()) {
-           return $result;
+            return $result;
         }
 
         if ($this->lowerBound > $value) {
diff --git a/src/Type/NullableType.php b/src/Type/NullableType.php
index 56b8a97..f3eb64e 100644
--- a/src/Type/NullableType.php
+++ b/src/Type/NullableType.php
@@ -18,7 +18,7 @@ public function __construct(TypeInterface $child)
 
     public function check(string $key, $value): ResultInterface
     {
-        if($value === null) {
+        if ($value === null) {
             return Result::valid();
         }