diff --git a/BUILDING.md b/BUILDING.md
index 31800bd66b0fc2..8a23e7e1be7c6b 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -324,13 +324,13 @@ You can execute the entire suite of tests for a given subsystem
 by providing the name of a subsystem:
 
 ```text
-$ tools/test.py -J child-process
+$ tools/test.py child-process
 ```
 
 You can also execute the tests in a tests directory (such as `test/message`):
 
 ```text
-$ tools/test.py -J test/message
+$ tools/test.py test/message
 ```
 
 If you want to check the other options, please refer to the help by using