diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ba4b548..c01b21f 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1615,6 +1615,10 @@
         Py_FileSystemDefaultEncoding = "utf-8";
         Py_HasFileSystemDefaultEncoding = 1;
     }
+    else if (_Py_GetForceASCII()) {
+        Py_FileSystemDefaultEncoding = "ascii";
+        Py_HasFileSystemDefaultEncoding = 1;
+    }
     else if (Py_FileSystemDefaultEncoding == NULL) {
         Py_FileSystemDefaultEncoding = get_locale_encoding();
         if (Py_FileSystemDefaultEncoding == NULL) {