diff --git a/gtsam_unstable/gtsam_unstable.h b/gtsam_unstable/gtsam_unstable.h
index 1aa655ce8..adb14f25d 100644
--- a/gtsam_unstable/gtsam_unstable.h
+++ b/gtsam_unstable/gtsam_unstable.h
@@ -4,6 +4,7 @@
 
 // specify the classes from gtsam we are using
 virtual class gtsam::Value;
+virtual class gtsam::LieScalar;
 virtual class gtsam::Point2;
 virtual class gtsam::Rot2;
 virtual class gtsam::Pose2;
@@ -367,6 +368,16 @@ virtual class DGroundConstraint : gtsam::NonlinearFactor {
   DGroundConstraint(size_t key, Vector constraint, const gtsam::noiseModel::Base* model);
 };
 
+#include <gtsam/base/LieScalar.h>
+
+#include <gtsam_unstable/dynamics/VelocityConstraint3.h>
+virtual class VelocityConstraint3 : gtsam::NonlinearFactor {
+  /** Standard constructor */
+  VelocityConstraint3(size_t key1, size_t key2, size_t velKey, double dt);
+
+  Vector evaluateError(const gtsam::LieScalar& x1, const gtsam::LieScalar& x2, const gtsam::LieScalar& v) const;
+};
+
 //*************************************************************************
 // nonlinear
 //*************************************************************************