diff --git a/Lib/test/test_ctypes/test_loading.py b/Lib/test/test_ctypes/test_loading.py
index 9f0547f4c955c0..59d7f51935f3cd 100644
--- a/Lib/test/test_ctypes/test_loading.py
+++ b/Lib/test/test_ctypes/test_loading.py
@@ -141,7 +141,7 @@ def test_load_hasattr(self):
     def test_load_dll_with_flags(self):
         _sqlite3 = import_helper.import_module("_sqlite3")
         src = _sqlite3.__file__
-        if src.partition(".")[0].lower().endswith("_d"):
+        if os.path.basename(src).partition(".")[0].lower().endswith("_d"):
             ext = "_d.dll"
         else:
             ext = ".dll"