diff --git a/contrib/systemd/README.txt b/contrib/systemd/README.txt
index 3225641f49612d41026bfe7fde7baeecf86acc07..31ae1638cb5b484fa124fcbfa4ca872c8fd87328 100644
--- a/contrib/systemd/README.txt
+++ b/contrib/systemd/README.txt
@@ -12,6 +12,9 @@ extends to the following listeners:
 The primary use case of this feature is to allow Asterisk to be started by
 other services through use of AMI, CLI or REST API.
 
+The examples and documentation assume that Asterisk was linked to libsystemd
+when compiled.  This integration is required for `Type=notify` and socket
+activation to work.
 
 Security
 ========