diff --git a/src/main/java/nl/knaw/dans/dvcli/command/NotificationTruncate.java b/src/main/java/nl/knaw/dans/dvcli/command/NotificationTruncate.java
index fdf4ddf..2e48dca 100644
--- a/src/main/java/nl/knaw/dans/dvcli/command/NotificationTruncate.java
+++ b/src/main/java/nl/knaw/dans/dvcli/command/NotificationTruncate.java
@@ -49,7 +49,7 @@ public NotificationTruncate(@NonNull Database database) {
 
     static class UserOptions {
         @CommandLine.Option(names = { "--user" }, required = true, 
-                description = "The user whose notifications to truncate.")
+                description = "The user database id (a number) whose notifications to truncate.")
         int user; // a number, preventing accidental SQL injection
         // This id is visible for 'superusers' in the Dataverse Dashboard