diff --git a/gtsam/base/concepts.h b/gtsam/base/concepts.h
index 2cccd46cb..4fa1108c9 100644
--- a/gtsam/base/concepts.h
+++ b/gtsam/base/concepts.h
@@ -18,7 +18,7 @@
 
 namespace gtsam {
 
-template <typename T> struct traits_x {};
+
 
 /**
  * @name Algebraic Structure Tags
@@ -35,6 +35,19 @@ struct vector_space_tag: public lie_group_tag {};
 struct multiplicative_group_tag {};
 struct additive_group_tag {};
 
+// TODO: Remove
+namespace traits {
+template<typename T>
+struct dimension;
+}
+template <typename T> struct traits_x {
+  // todo: remove anything in here ASAP.
+  // This is just here during development to avoid compilation
+  // errors while implmenting traits for everything.
+  enum { dimension = traits::dimension<T>::value };
+  typedef manifold_tag structure_category;
+};
+
 
 namespace internal {
 
diff --git a/gtsam/base/numericalDerivative.h b/gtsam/base/numericalDerivative.h
index b2c163c2d..8e1989d53 100644
--- a/gtsam/base/numericalDerivative.h
+++ b/gtsam/base/numericalDerivative.h
@@ -28,6 +28,7 @@
 #pragma GCC diagnostic pop
 #endif
 
+#include <gtsam/base/concepts.h>
 #include <gtsam/base/Matrix.h>
 #include <gtsam/base/Manifold.h>
 #include <gtsam/linear/VectorValues.h>
@@ -110,12 +111,12 @@ Matrix numericalDerivative11(boost::function<Y(const X&)> h, const X& x,
     double delta = 1e-5) {
   using namespace traits;
 
-  BOOST_STATIC_ASSERT_MSG(traits::is_manifold<Y>::value,
+  BOOST_STATIC_ASSERT_MSG( (typename boost::is_same< typename traits_x<X>::structure_category, gtsam::manifold_tag>::value),
       "Template argument Y must be a manifold type.");
   typedef DefaultChart<Y> ChartY;
   typedef typename ChartY::vector TangentY;
 
-  BOOST_STATIC_ASSERT_MSG(traits::is_manifold<X>::value,
+  BOOST_STATIC_ASSERT_MSG( (typename boost::is_same<traits_x<X>::structure_category, gtsam::manifold_tag>::value),
       "Template argument X must be a manifold type.");
   static const int N = traits::dimension<X>::value;
   BOOST_STATIC_ASSERT_MSG(N>0, "Template argument X must be fixed-size type.");
diff --git a/gtsam/nonlinear/Expression-inl.h b/gtsam/nonlinear/Expression-inl.h
index d6dc5088d..b91bbd478 100644
--- a/gtsam/nonlinear/Expression-inl.h
+++ b/gtsam/nonlinear/Expression-inl.h
@@ -21,6 +21,7 @@
 
 #include <gtsam_unstable/nonlinear/CallRecord.h>
 #include <gtsam/nonlinear/Values.h>
+#include <gtsam/base/concepts.h>
 #include <gtsam/base/Testable.h>
 #include <gtsam/base/Manifold.h>
 #include <gtsam/base/OptionalJacobian.h>
@@ -143,7 +144,7 @@ void handleLeafCase(const Eigen::MatrixBase<Derived>& dTdA,
  */
 template<class T>
 class ExecutionTrace {
-  static const int Dim = traits::dimension<T>::value;
+  static const int Dim = traits_x<T>::dimension;
   enum {
     Constant, Leaf, Function
   } kind;
@@ -624,7 +625,7 @@ struct FunctionalNode {
     /// Provide convenience access to Record storage and implement
     /// the virtual function based interface of CallRecord using the CallRecordImplementor
     struct Record: public internal::CallRecordImplementor<Record,
-        traits::dimension<T>::value>, public Base::Record {
+        traits_x<T>::dimension>, public Base::Record {
       using Base::Record::print;
       using Base::Record::startReverseAD4;
       using Base::Record::reverseAD4;