PyString_AsString is permissive and accepts unicode strings.
Replace it with PyUnicode_AsString when the argument is known to be a str.
diff --git a/Python/peephole.c b/Python/peephole.c
index d012d39..9f1e642 100644
--- a/Python/peephole.c
+++ b/Python/peephole.c
@@ -407,7 +407,7 @@
case LOAD_NAME:
case LOAD_GLOBAL:
j = GETARG(codestr, i);
- name = PyString_AsString(PyTuple_GET_ITEM(names, j));
+ name = PyUnicode_AsString(PyTuple_GET_ITEM(names, j));
h = load_global(codestr, i, name, consts);
if (h < 0)
goto exitUnchanged;