diff --git a/test/core/Container.js b/test/core/Container.js
index afc767c..af9efae 100644
--- a/test/core/Container.js
+++ b/test/core/Container.js
@@ -301,6 +301,12 @@
             {
                 container.swapChildren(child1, child2);
             });
+
+            // second call required to complete returned index coverage
+            assertCallToOnChildrenChanged(container, 0, () =>
+            {
+                container.swapChildren(child1, child2);
+            });
         });
 
         it('should not call onChildrenChange if supplied children are equal', () =>