diff --git a/test/language/expressions/tagged-template/invalid-escape-sequences.js b/test/language/expressions/tagged-template/invalid-escape-sequences.js
index a79c644e27..479a9c8aa7 100644
--- a/test/language/expressions/tagged-template/invalid-escape-sequences.js
+++ b/test/language/expressions/tagged-template/invalid-escape-sequences.js
@@ -15,6 +15,16 @@ esid: sec-template-literal-lexical-components
   assert.sameValue(strs.raw[0], '\\1');
 })`\1`;
 
+(strs => {
+  assert.sameValue(strs[0], undefined, 'Cooked template value should be undefined for illegal escape sequences');
+  assert.sameValue(strs.raw[0], '\\8');
+})`\8`;
+
+(strs => {
+  assert.sameValue(strs[0], undefined, 'Cooked template value should be undefined for illegal escape sequences');
+  assert.sameValue(strs.raw[0], '\\9');
+})`\9`;
+
 (strs => {
   assert.sameValue(strs[0], undefined, 'Cooked template value should be undefined for illegal escape sequences');
   assert.sameValue(strs.raw[0], '\\xg');