diff --git a/html/semantics/tabular-data/the-tbody-element/deleteRow.html b/html/semantics/tabular-data/the-tbody-element/deleteRow.html
index 820c7dd87b0553..c81abd82600f65 100644
--- a/html/semantics/tabular-data/the-tbody-element/deleteRow.html
+++ b/html/semantics/tabular-data/the-tbody-element/deleteRow.html
@@ -43,4 +43,12 @@
   });
 }, "HTMLTableSectionElement deleteRow(-2)");
 
+test(function () {
+  assert_equals(tbody.rows.length, 1);
+  tbody.deleteRow(-1);
+  assert_equals(tbody.rows.length, 0);
+  tbody.deleteRow(-1);
+  assert_equals(tbody.rows.length, 0);
+}, "HTMLTableSectionElement deleteRow(-1) with no rows");
+
 </script>
diff --git a/html/semantics/tabular-data/the-tbody-element/insertRow.html b/html/semantics/tabular-data/the-tbody-element/insertRow.html
index 1318323986e00d..4c13db7aa5f6b7 100644
--- a/html/semantics/tabular-data/the-tbody-element/insertRow.html
+++ b/html/semantics/tabular-data/the-tbody-element/insertRow.html
@@ -35,6 +35,12 @@
   assert_equals(tbody.rows.length, 4);
 }, "HTMLTableSectionElement insertRow()");
 
+test(function () {
+  var trEle = tbody.insertRow(tbody.rows.length);
+  assert_equals(tbody.rows[tbody.rows.length - 1], trEle);
+  assert_equals(tbody.rows.length, 5);
+}, "HTMLTableSectionElement insertRow(rows.length)");
+
 test(function () {
   assert_throws("IndexSizeError", function () {
     tbody.insertRow(-2);