diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index b5fff7f..c26ca80 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -473,6 +473,7 @@
                 zinfo.external_attr = 0o600 << 16
                 zipfp.writestr(zinfo, content)
 
+            arcname = arcname.replace(os.sep, "/")
             targetpath = os.path.join('target', 'subdir', 'subsub')
             correctfile = os.path.join(targetpath, *fixedname.split('/'))