diff --git a/content/html/content/test/test_bug418756.html b/content/html/content/test/test_bug418756.html
index 56f15def43e..ed51300956b 100644
--- a/content/html/content/test/test_bug418756.html
+++ b/content/html/content/test/test_bug418756.html
@@ -276,11 +276,61 @@ for each (let n in [1, 2, 3]) {
     is(g.defaultChecked, n == 1 && (group1.indexOf(g) == 0 ||
                                     group1.indexOf(g) == 2),
        "group" + n + "[" + window["group"+n].indexOf(g) +
-       "] defaultChecked wrong pass 11");
+       "] defaultChecked wrong pass 12");
     is(g.checked, n == 1 && (group1.indexOf(g) == 1 ||
                              group1.indexOf(g) == 0),
        "group" + n + "[" + window["group"+n].indexOf(g) +
-       "] checked wrong pass 11");
+       "] checked wrong pass 12");
+  }
+}
+
+next = group2[1].nextSibling;
+p = group2[1].parentNode;
+p.removeChild(group2[1]);
+p.insertBefore(group2[1], next);
+group2[0].checked = true;
+for each (let n in [1, 2, 3]) {
+  for each (let g in window["group"+n]) {
+    is(g.defaultChecked, n == 1 && (group1.indexOf(g) == 0 ||
+                                    group1.indexOf(g) == 2),
+       "group" + n + "[" + window["group"+n].indexOf(g) +
+       "] defaultChecked wrong pass 13");
+    is(g.checked, (n == 1 && (group1.indexOf(g) == 1 ||
+                              group1.indexOf(g) == 0)) ||
+                  (n == 2 && group2.indexOf(g) == 0), 
+       "group" + n + "[" + window["group"+n].indexOf(g) +
+       "] checked wrong pass 13");
+  }
+}
+
+p.insertBefore(group2[1], next);
+for each (let n in [1, 2, 3]) {
+  for each (let g in window["group"+n]) {
+    is(g.defaultChecked, n == 1 && (group1.indexOf(g) == 0 ||
+                                    group1.indexOf(g) == 2),
+       "group" + n + "[" + window["group"+n].indexOf(g) +
+       "] defaultChecked wrong pass 14");
+    is(g.checked, (n == 1 && (group1.indexOf(g) == 1 ||
+                              group1.indexOf(g) == 0)) ||
+                  (n == 2 && group2.indexOf(g) == 0), 
+       "group" + n + "[" + window["group"+n].indexOf(g) +
+       "] checked wrong pass 14");
+  }
+}
+
+group2[1].defaultChecked = true;
+for each (let n in [1, 2, 3]) {
+  for each (let g in window["group"+n]) {
+    is(g.defaultChecked, (n == 1 && (group1.indexOf(g) == 0 ||
+                                     group1.indexOf(g) == 2)) ||
+                         (n == 2 && group2.indexOf(g) == 1),
+       "group" + n + "[" + window["group"+n].indexOf(g) +
+       "] defaultChecked wrong pass 15");
+    is(g.checked, (n == 1 && (group1.indexOf(g) == 1 ||
+                              group1.indexOf(g) == 0)) ||
+                  (n == 2 && group2.indexOf(g) == 0), 
+       "group" + n + "[" + window["group"+n].indexOf(g) +
+       "] checked wrong pass 15");
   }
 }