diff --git a/Lib/test/test_pep3120.py b/Lib/test/test_pep3120.py
index d4c20ef1d0b..5b63998cf59 100644
--- a/Lib/test/test_pep3120.py
+++ b/Lib/test/test_pep3120.py
@@ -19,8 +19,8 @@ class PEP3120Test(unittest.TestCase):
         try:
             import test.badsyntax_pep3120
         except SyntaxError as msg:
-            msg = str(msg)
-            self.assertTrue('Non-UTF-8 code starting with' in msg)
+            msg = str(msg).lower()
+            self.assertTrue('utf-8' in msg)
         else:
             self.fail("expected exception didn't occur")