diff --git a/BUILDING.md b/BUILDING.md
index d6ca30104b77f4..979ae68d7854d0 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -336,13 +336,13 @@ 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