diff --git a/README.md b/README.md
index 4d26cb1c4..ac53f2f95 100644
--- a/README.md
+++ b/README.md
@@ -39,5 +39,5 @@ You can try the JavaScript version in this [BBCodes + other stuff demo](https://
 The following tools are used during development.
 
  - [phpunit/phpunit](https://phpunit.de/) 9.6.13 runs a full suite of tests before every commit.
- - [code-lts/doctum](https://github.com/code-lts/doctum) 5.5.2 generates the [API docs](https://s9e.github.io/TextFormatter/api/).
+ - [code-lts/doctum](https://github.com/code-lts/doctum) 5.5.3 generates the [API docs](https://s9e.github.io/TextFormatter/api/).
  - Scrutinizer is used for code tracking.