diff --git a/crates/cli/src/commands/event.rs b/crates/cli/src/commands/event.rs
index 28f706a..ddd553b 100644
--- a/crates/cli/src/commands/event.rs
+++ b/crates/cli/src/commands/event.rs
@@ -474,6 +474,24 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_parse_event_list_deduplicates_shorthand_and_canonical_names() {
+        let events = parse_event_list(&[
+            "put,s3:ObjectCreated:*".to_string(),
+            "GET,s3:ObjectAccessed:*".to_string(),
+            "delete,s3:ObjectRemoved:*".to_string(),
+        ]);
+
+        assert_eq!(
+            events,
+            vec![
+                "s3:ObjectAccessed:*".to_string(),
+                "s3:ObjectCreated:*".to_string(),
+                "s3:ObjectRemoved:*".to_string(),
+            ]
+        );
+    }
+
     #[test]
     fn test_infer_target_from_arn() {
         assert_eq!(