diff --git a/components/lock.rst b/components/lock.rst
index b8ba38c8fc7..1bcdc51f80e 100644
--- a/components/lock.rst
+++ b/components/lock.rst
@@ -405,7 +405,8 @@ Store                                                       Scope   Blocking  Ex
 
     Symfony includes two other special stores that are mostly useful for testing:
     ``InMemoryStore``, which saves locks in memory during a process, and ``NullStore``,
-    which doesn't persist anything.
+    which doesn't persist anything. To activate either one, simply set the ``LOCK_DSN`` to
+    ``null`` or ``in-memory``.
 
 .. versionadded:: 7.2