diff --git a/Lib/types.py b/Lib/types.py
index 11bd4b4ce6f..8a07950f7e9 100644
--- a/Lib/types.py
+++ b/Lib/types.py
@@ -26,9 +26,9 @@
 StringType = str
 try:
     UnicodeType = unicode
-    StringTypes = [StringType, UnicodeType]
+    StringTypes = (StringType, UnicodeType)
 except NameError:
-    StringTypes = [StringType]
+    StringTypes = (StringType,)
 
 BufferType = type(buffer(''))