diff --git a/hive-c0re/src/agent_config/tool_groups.rs b/hive-c0re/src/agent_config/tool_groups.rs
index c1379dd8..404a5854 100644
--- a/hive-c0re/src/agent_config/tool_groups.rs
+++ b/hive-c0re/src/agent_config/tool_groups.rs
@@ -202,6 +202,13 @@ mod tests {
         assert_eq!(map["alice"], vec!["messaging".to_owned()]);
     }
 
+    #[test]
+    fn prune_unknown_keeps_a_hand_edited_differently_cased_known_name() {
+        let mut map = BTreeMap::from([("alice".to_owned(), vec!["Messaging".to_owned()])]);
+        assert!(!prune_unknown(&mut map));
+        assert_eq!(map["alice"], vec!["Messaging".to_owned()]);
+    }
+
     #[test]
     fn prune_unknown_drops_unrecognised_name() {
         let mut map = BTreeMap::from([("alice".to_owned(), vec!["diagnostics".to_owned()])]);