diff --git a/README.md b/README.md
index 5967702..9085e36 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,10 @@ In case you don't own the code which you want to be considered deprecated, use [
 class ThirdPartyClass {}
 ```
 
+## Custom deprecation markers
+
+You can implement extensions to support even e.g. custom `#[MyDeprecated]` attribute.  [Learn more](https://phpstan.org/developing-extensions/custom-deprecations).
+
 
 ## Custom deprecated scopes