diff --git a/man/systemd-sysext.xml b/man/systemd-sysext.xml
index d7f5d2f37f8..42e8e12df97 100644
--- a/man/systemd-sysext.xml
+++ b/man/systemd-sysext.xml
@@ -108,7 +108,9 @@
accessed.
Note that there is no concept of enabling/disabling installed system extension images: all
- installed extension images are automatically activated at boot.
+ installed extension images are automatically activated at boot. However, you can place a symlink
+ to /dev/null in /etc/extensions/ to "mask" an image with
+ the same name in a folder with lower precedence.
A simple mechanism for version compatibility is enforced: a system extension image must carry a
/usr/lib/extension-release.d/extension-release.$name