diff --git a/Lib/test/test_winreg.py b/Lib/test/test_winreg.py
index 3f73c74..174d7bc 100644
--- a/Lib/test/test_winreg.py
+++ b/Lib/test/test_winreg.py
@@ -73,7 +73,7 @@
 
         key = OpenKey(root_key, test_key_name)
         # Read the sub-keys
-        with OpenKey(key, "sub_key") as sub_key:
+        with OpenKey(key, subkeystr) as sub_key:
             # Check I can enumerate over the values.
             index = 0
             while 1: