diff --git a/docs/schema-definition.md b/docs/schema-definition.md
index e3c74b5ed..35b7c2b70 100644
--- a/docs/schema-definition.md
+++ b/docs/schema-definition.md
@@ -171,6 +171,8 @@ final class Types
             return self::$types[$typeName];
         }
 
+        // For every type, this class must define a method with the same name
+        // but the first letter is in lower case.
         $methodName = match ($typeName) {
             'ID' => 'id',
             default => lcfirst($typeName),
@@ -190,8 +192,11 @@ final class Types
     /** @return Type&NamedType */
     private static function byClassName(string $className): Type
     {
-        $parts = \explode('\\', $className);
-        $typeName = \preg_replace('~Type$~', '', $parts[\count($parts) - 1]);
+        $classNameParts = explode('\\', $className);
+        $baseClassName = end($classNameParts);
+        // All type classes must use the suffix Type.
+        // This prevents name collisions between types and PHP keywords.
+        $typeName = preg_replace('~Type$~', '', $baseClassName);
 
         // Type loading is very similar to PHP class loading, but keep in mind
         // that the **typeLoader** must always return the same instance of a type.
diff --git a/examples/01-blog/Blog/Types.php b/examples/01-blog/Blog/Types.php
index d9451a4f8..d1c108458 100644
--- a/examples/01-blog/Blog/Types.php
+++ b/examples/01-blog/Blog/Types.php
@@ -40,6 +40,8 @@ public static function load(string $typeName): Type
             return self::$types[$typeName];
         }
 
+        // For every type, this class must define a method with the same name
+        // but the first letter is in lower case.
         switch ($typeName) {
             case 'ID':
                 $methodName = 'id';
@@ -66,9 +68,11 @@ public static function load(string $typeName): Type
      */
     private static function byClassName(string $className): Type
     {
-        $parts = \explode('\\', $className);
-
-        $typeName = \preg_replace('~Type$~', '', $parts[\count($parts) - 1]);
+        $classNameParts = \explode('\\', $className);
+        $baseClassName = end($classNameParts);
+        // All type classes must use the suffix Type.
+        // This prevents name collisions between types and PHP keywords.
+        $typeName = \preg_replace('~Type$~', '', $baseClassName);
         assert(is_string($typeName), 'regex is statically known to be correct');
 
         // Type loading is very similar to PHP class loading, but keep in mind