diff --git a/python/handwritten/common.h b/python/handwritten/common.h
new file mode 100644
index 000000000..72d2ae846
--- /dev/null
+++ b/python/handwritten/common.h
@@ -0,0 +1,31 @@
+/* ----------------------------------------------------------------------------
+
+ * GTSAM Copyright 2010, Georgia Tech Research Corporation,
+ * Atlanta, Georgia 30332-0415
+ * All Rights Reserved
+ * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+
+ * See LICENSE for the license information
+
+ * -------------------------------------------------------------------------- */
+
+/**
+ * @brief common macros used by handwritten exports of the python module
+ * @author Ellon Paiva Mendes (LAAS-CNRS)
+ **/
+
+#pragma once
+
+ /* Fix to avoid registration warnings */
+// Solution taken from https://github.com/BVLC/caffe/pull/4069/commits/673e8cfc0b8f05f9fa3ebbad7cc6202822e5d9c5 
+#define REGISTER_SHARED_PTR_TO_PYTHON(PTR) do { \
+  const boost::python::type_info info = \
+    boost::python::type_id<boost::shared_ptr<PTR > >(); \
+  const boost::python::converter::registration* reg = \
+    boost::python::converter::registry::query(info); \
+  if (reg == NULL) { \
+    boost::python::register_ptr_to_python<boost::shared_ptr<PTR > >(); \
+  } else if ((*reg).m_to_python == NULL) { \
+    boost::python::register_ptr_to_python<boost::shared_ptr<PTR > >(); \
+  } \
+} while (0)
diff --git a/python/handwritten/linear/NoiseModel.cpp b/python/handwritten/linear/NoiseModel.cpp
index 3b7896a27..00fa9d74f 100644
--- a/python/handwritten/linear/NoiseModel.cpp
+++ b/python/handwritten/linear/NoiseModel.cpp
@@ -28,19 +28,7 @@
 
 #include "gtsam/linear/NoiseModel.h"
 
-/* Fix to avoid registration warnings */
-// Solution taken from https://github.com/BVLC/caffe/pull/4069/commits/673e8cfc0b8f05f9fa3ebbad7cc6202822e5d9c5 
-#define REGISTER_SHARED_PTR_TO_PYTHON(PTR) do { \
-  const boost::python::type_info info = \
-    boost::python::type_id<boost::shared_ptr<PTR > >(); \
-  const boost::python::converter::registration* reg = \
-    boost::python::converter::registry::query(info); \
-  if (reg == NULL) { \
-    boost::python::register_ptr_to_python<boost::shared_ptr<PTR > >(); \
-  } else if ((*reg).m_to_python == NULL) { \
-    boost::python::register_ptr_to_python<boost::shared_ptr<PTR > >(); \
-  } \
-} while (0)
+#include "python/handwritten/common.h"
 
 using namespace boost::python;
 using namespace gtsam;
diff --git a/python/handwritten/navigation/ImuFactor.cpp b/python/handwritten/navigation/ImuFactor.cpp
index d7c295894..0cf3062b5 100644
--- a/python/handwritten/navigation/ImuFactor.cpp
+++ b/python/handwritten/navigation/ImuFactor.cpp
@@ -22,20 +22,7 @@
 #include "gtsam/navigation/ImuFactor.h"
 #include "gtsam/navigation/GPSFactor.h"
 
-/* Fix to avoid registration warnings */
-// Solution taken from https://github.com/BVLC/caffe/pull/4069/commits/673e8cfc0b8f05f9fa3ebbad7cc6202822e5d9c5 
-#define REGISTER_SHARED_PTR_TO_PYTHON(PTR) do { \
-  const boost::python::type_info info = \
-    boost::python::type_id<boost::shared_ptr<PTR > >(); \
-  const boost::python::converter::registration* reg = \
-    boost::python::converter::registry::query(info); \
-  if (reg == NULL) { \
-    boost::python::register_ptr_to_python<boost::shared_ptr<PTR > >(); \
-  } else if ((*reg).m_to_python == NULL) { \
-    boost::python::register_ptr_to_python<boost::shared_ptr<PTR > >(); \
-  } \
-} while (0)
-
+#include "python/handwritten/common.h"
 
 using namespace boost::python;
 using namespace gtsam;