diff --git a/src/interface.jl b/src/interface.jl
index de0ad27..3fddc26 100644
--- a/src/interface.jl
+++ b/src/interface.jl
@@ -1,6 +1,6 @@
 const DEFAULT_GRADIENT_TRACER = GradientTracer{IndexSetGradientPattern{Int,BitSet}}
 const DEFAULT_HESSIAN_TRACER = HessianTracer{
-    IndexSetHessianPattern{Int,BitSet,Set{Tuple{Int,Int}},NotShared}
+    DictHessianPattern{Int,BitSet,Dict{Int,BitSet},NotShared}
 }
 
 #==================#