diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index 1e782cf..1cacdea 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -213,6 +213,9 @@
         asm = dis_single('"\u0061\uffff"[1]')
         self.assertIn("('\\uffff')", asm)
         self.assertNotIn('BINARY_SUBSCR', asm)
+        asm = dis_single('"\U00012345abcdef"[3]')
+        self.assertIn("('c')", asm)
+        self.assertNotIn('BINARY_SUBSCR', asm)
 
         # invalid code doesn't get optimized
         # out of range