diff --git a/TODO.md b/TODO.md
index 7e39901..fe9d849 100644
--- a/TODO.md
+++ b/TODO.md
@@ -2,19 +2,40 @@
 
 ## Things to do
 
-### Fix PHPStan errors
-
-- [x] `Undefined variable: $isEqual` - replace `eval()` with callable
-  in [src/Utilities/Regex.php:151](./src/Utilities/Regex.php)
-- [x] `Unsafe usage of new static()` - chose one
-  of [possible solutions](https://phpstan.org/blog/solving-phpstan-error-unsafe-usage-of-new-static) -
-  in [src/Type/Base/BaseType.php:37](./src/Type/Base/BaseType.php)
-- [x] `Unsafe usage of new static()` - chose one
-  of [possible solutions](https://phpstan.org/blog/solving-phpstan-error-unsafe-usage-of-new-static) -
-  in [src/Exception/Base/UnknownTypeException.php:40](./src/Exception/Base/UnknownTypeException.php)
-- [x] Clean and remove the [phpstan-baseline.neon](phpstan-baseline.neon) file finally
-
-### Refactoring
-
-- [ ] Replace `Meritoo\Common\Type\OopVisibilityType` class
-  with [PHP enum](https://www.php.net/manual/en/language.types.enumerations.php)
+- [ ] Bump PHP version: `8.0` -> `8.2`
+- [ ] Run GitHub Actions for `8.2`, `8.3`, and `8.4` (do not run for `8.0` and `8.1`)
+- [ ] Fix deprecations when running PHPUnit tests
+- [ ] Replace all the `*Type` classes
+  with [enumerations](https://www.php.net/manual/en/language.types.enumerations.php) (
+  classes that extend `Meritoo\Common\Type\Base\BaseType`)
+
+  **A new `enum`:**
+
+  ```php
+  <?php
+  
+  declare(strict_types=1);
+  
+  namespace Meritoo\Common\Enums;
+  
+  enum OopVisibility: string
+  {
+      case Private = '3';
+      case Protected = '2';
+      case Public = '1';
+  }
+  ```
+
+  **A new piece of `[CHANGELOG.md](CHANGELOG.md)`:**
+
+  6. Replace all the `*Type` classes
+     with [enumerations](https://www.php.net/manual/en/language.types.enumerations.php) (
+     classes that extend `Meritoo\Common\Type\Base\BaseType`)
+
+     | Before                    | After                |
+                                                                                  |---------------------------|----------------------|
+     | `class OopVisibilityType` | `enum OopVisibility` |
+     | ...                       | ...                  |
+     | ...                       | ...                  |
+
+- [ ] Bump PHPStan level: `1` -> `2`