diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 5b7cd20..f45d7dc 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1190,7 +1190,7 @@
     d = PyModule_GetDict(m);
     if (PyDict_GetItemString(d, "__file__") == NULL) {
         PyObject *f;
-        f = PyUnicode_DecodeFSDefault(filename);
+        f = PyUnicode_FromString(filename);
         if (f == NULL)
             return -1;
         if (PyDict_SetItemString(d, "__file__", f) < 0) {