diff --git a/crates/cli/src/commands/event.rs b/crates/cli/src/commands/event.rs
index 28f706a..15320a5 100644
--- a/crates/cli/src/commands/event.rs
+++ b/crates/cli/src/commands/event.rs
@@ -474,6 +474,13 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_parse_event_list_deduplicates_shorthand_and_canonical_values() {
+        let events = parse_event_list(&["put,s3:ObjectCreated:*".to_string(), "PUT".to_string()]);
+
+        assert_eq!(events, vec!["s3:ObjectCreated:*".to_string()]);
+    }
+
     #[test]
     fn test_infer_target_from_arn() {
         assert_eq!(