diff --git a/Library/LaunchAgents/com.github.erikw.restic-automatic-backup.plist b/Library/LaunchAgents/com.github.erikw.restic-automatic-backup.plist
index f859942..540223a 100644
--- a/Library/LaunchAgents/com.github.erikw.restic-automatic-backup.plist
+++ b/Library/LaunchAgents/com.github.erikw.restic-automatic-backup.plist
@@ -7,6 +7,7 @@
 		<key>Label</key>
 		<string>com.github.erikw.restic-automatic-backup</string>
 		<key>ProgramArguments</key>
+		<!-- exec in subshell to 1) source *.env.sh 2) expand $HOME to logpath (ref. https://apple.stackexchange.com/a/365880/197493) -->
 		<array>
 			<string>/bin/bash</string>
 			<string>-c</string>