diff --git a/src/polysolve/nonlinear/CMakeLists.txt b/src/polysolve/nonlinear/CMakeLists.txt
index fc46887d..c842dbe3 100644
--- a/src/polysolve/nonlinear/CMakeLists.txt
+++ b/src/polysolve/nonlinear/CMakeLists.txt
@@ -5,6 +5,8 @@ set(SOURCES
 	Solver.cpp
 	Problem.hpp
 	Problem.cpp
+	PostStepData.hpp
+	PostStepData.cpp
 )
 
 source_group(TREE "${CMAKE_CURRENT_SOURCE_DIR}" PREFIX "Source Files" FILES ${SOURCES})
diff --git a/src/polysolve/nonlinear/PostStepData.cpp b/src/polysolve/nonlinear/PostStepData.cpp
new file mode 100644
index 00000000..a411dce4
--- /dev/null
+++ b/src/polysolve/nonlinear/PostStepData.cpp
@@ -0,0 +1,11 @@
+#include "PostStepData.hpp"
+
+namespace polysolve::nonlinear
+{
+    PostStepData::PostStepData(const int iter_num,
+                               const Eigen::VectorXd &x,
+                               const Eigen::VectorXd &grad)
+        : iter_num(iter_num), x(x), grad(grad)
+    {
+    }
+} // namespace polysolve::nonlinear
diff --git a/src/polysolve/nonlinear/PostStepData.hpp b/src/polysolve/nonlinear/PostStepData.hpp
new file mode 100644
index 00000000..dc5ccdba
--- /dev/null
+++ b/src/polysolve/nonlinear/PostStepData.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <polysolve/Types.hpp>
+
+namespace polysolve::nonlinear
+{
+
+    class PostStepData
+    {
+    public:
+        PostStepData(const int iter_num,
+                     const Eigen::VectorXd &x,
+                     const Eigen::VectorXd &grad);
+
+        const int iter_num;
+        const Eigen::VectorXd &x;
+        const Eigen::VectorXd &grad;
+    };
+} // namespace polysolve::nonlinear
diff --git a/src/polysolve/nonlinear/Problem.hpp b/src/polysolve/nonlinear/Problem.hpp
index 6cb15a3e..33e535c1 100644
--- a/src/polysolve/nonlinear/Problem.hpp
+++ b/src/polysolve/nonlinear/Problem.hpp
@@ -2,6 +2,8 @@
 
 #include <polysolve/Types.hpp>
 
+#include "PostStepData.hpp"
+
 #include <cppoptlib/problem.h>
 
 #include <memory>
@@ -33,7 +35,7 @@ namespace polysolve::nonlinear
 
         virtual void line_search_begin(const TVector &x0, const TVector &x1) {}
         virtual void line_search_end() {}
-        virtual void post_step(const int iter_num, const TVector &x) {}
+        virtual void post_step(const PostStepData &data) {}
 
         virtual void set_project_to_psd(bool val) {}
 
diff --git a/src/polysolve/nonlinear/Solver.cpp b/src/polysolve/nonlinear/Solver.cpp
index 5e995f99..38d34f87 100644
--- a/src/polysolve/nonlinear/Solver.cpp
+++ b/src/polysolve/nonlinear/Solver.cpp
@@ -1,6 +1,8 @@
 
 #include "Solver.hpp"
 
+#include "PostStepData.hpp"
+
 #include "descent_strategies/BFGS.hpp"
 #include "descent_strategies/Newton.hpp"
 #include "descent_strategies/GradientDescent.hpp"
@@ -191,7 +193,7 @@ namespace polysolve::nonlinear
             objFunc.solution_changed(x);
         }
 
-        objFunc.post_step(this->m_current.iterations, x);
+        objFunc.post_step(PostStepData(this->m_current.iterations, x, grad));
 
         const auto g_norm_tol = this->m_stop.gradNorm;
         this->m_stop.gradNorm = first_grad_norm_tol;
@@ -371,7 +373,7 @@ namespace polysolve::nonlinear
                 m_logger.debug("[{}][{}] Objective decided to stop", name(), m_line_search->name());
             }
 
-            objFunc.post_step(this->m_current.iterations, x);
+            objFunc.post_step(PostStepData(this->m_current.iterations, x, grad));
 
             if (f_delta < this->m_stop.fDelta)
                 f_delta_step_cnt++;