diff --git a/Lib/dis.py b/Lib/dis.py
index 5a74b3a..35ae595 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -9,6 +9,9 @@
 __all__ = ["dis","disassemble","distb","disco"] + _opcodes_all
 del _opcodes_all
 
+_have_code = (types.MethodType, types.FunctionType, types.CodeType,
+              types.ClassType, type)
+
 def dis(x=None):
     """Disassemble classes, methods, functions, or code.
 
@@ -28,10 +31,7 @@
         items = x.__dict__.items()
         items.sort()
         for name, x1 in items:
-            if type(x1) in (types.MethodType,
-                            types.FunctionType,
-                            types.CodeType,
-                            types.ClassType):
+            if isinstance(x1, _have_code):
                 print "Disassembly of %s:" % name
                 try:
                     dis(x1)