diff --git a/gtsam/nonlinear/NonlinearFactor.h b/gtsam/nonlinear/NonlinearFactor.h
index 725117748..2d3a13766 100644
--- a/gtsam/nonlinear/NonlinearFactor.h
+++ b/gtsam/nonlinear/NonlinearFactor.h
@@ -22,6 +22,7 @@
 #pragma once
 
 #include <gtsam/nonlinear/Values.h>
+#include <gtsam/hybrid/HybridValues.h>
 #include <gtsam/linear/NoiseModel.h>
 #include <gtsam/linear/JacobianFactor.h>
 #include <gtsam/inference/Factor.h>
diff --git a/gtsam/nonlinear/nonlinear.i b/gtsam/nonlinear/nonlinear.i
index 5d15c1163..b684b1aad 100644
--- a/gtsam/nonlinear/nonlinear.i
+++ b/gtsam/nonlinear/nonlinear.i
@@ -127,6 +127,7 @@ virtual class NonlinearFactor : gtsam::Factor {
   // NonlinearFactor
   bool equals(const gtsam::NonlinearFactor& other, double tol) const;
   double error(const gtsam::Values& c) const;
+  double error(const gtsam::HybridValues& c) const;
   size_t dim() const;
   bool active(const gtsam::Values& c) const;
   gtsam::GaussianFactor* linearize(const gtsam::Values& c) const;