--- syb-with-class-0.5.1/Data/Generics/SYB/WithClass/Derive.hs~	2010-01-24 08:12:31.000000000 -0800
+++ syb-with-class-0.5.1/Data/Generics/SYB/WithClass/Derive.hs	2010-01-24 08:12:25.000000000 -0800
@@ -175,6 +175,7 @@
        ]
      ])
  where notTyVar (VarT _) = False
+       notTyVar (ConT n) | n == name = False
        notTyVar _        = True
        types = [ t | (_, _, _, ts) <- cons, t <- ts, notTyVar t ]