diff --git a/4.2.3-uMatrix.md b/4.2.3-uMatrix.md
index 59cac1a..31854f6 100644
--- a/4.2.3-uMatrix.md
+++ b/4.2.3-uMatrix.md
@@ -4,6 +4,7 @@ Example: blocking [.cm](https://en.wikipedia.org/wiki/.cm) (the [ccTLD](https://
 
 ```
 * cm * block
+cm 1st-party * block
 ```
 
 For ABP-compatible syntax, this would be: