diff --git a/src/logic/future_moves.rs b/src/logic/future_moves.rs
index 4903a62..7f203f3 100644
--- a/src/logic/future_moves.rs
+++ b/src/logic/future_moves.rs
@@ -374,7 +374,7 @@ mod tests {
             lazy_children: false,
         });
 
-        futm.current_root = Some(0);
+        futm.update_root_idx_raw(0);
 
         // child 1
         futm.arena.push(Move::new(
@@ -442,9 +442,23 @@ mod tests {
             lazy_children: false,
         });
 
-        futm.current_root = Some(0);
+        futm.update_root_idx_raw(0);
 
         futm.extend_layers();
         assert_eq!(futm.arena_len(), 5);
+
+        // move to a child
+        futm.update_root_idx_raw(1);
+        futm.refocus_tree();
+        assert_eq!(futm.arena_len(), 1);
+
+        // make sure current_root is properly updated
+        assert_eq!(futm.current_root, Some(0));
+
+        futm.extend_layers();
+        assert!(
+            futm.arena_len() > 1,
+            "extend_layer didn't grow arena after refocus"
+        );
     }
 }