diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..1614457d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+# VIM
+.*.sw?
diff --git a/urdf/CMakeLists.txt b/urdf/CMakeLists.txt
index 6d706bc1..a109db0f 100644
--- a/urdf/CMakeLists.txt
+++ b/urdf/CMakeLists.txt
@@ -53,6 +53,8 @@ if(CATKIN_ENABLE_TESTING)
   find_package(catkin REQUIRED COMPONENTS rostest)
   add_rostest_gtest(test_urdf_parser test/test_robot_model_parser.launch test/test_robot_model_parser.cpp)
   target_link_libraries(test_urdf_parser ${PROJECT_NAME})
+
+  catkin_add_gtest(urdfdom_compatibility_test test/urdfdom_compatibility.cpp)
 endif()
 
 # no idea how CATKIN does this
diff --git a/urdf/test/urdfdom_compatibility.cpp b/urdf/test/urdfdom_compatibility.cpp
new file mode 100644
index 00000000..13524811
--- /dev/null
+++ b/urdf/test/urdfdom_compatibility.cpp
@@ -0,0 +1,53 @@
+/*********************************************************************
+* Software License Agreement (BSD License)
+*
+*  Copyright (c) 2017 Open Source Robotics Foundation
+*  All rights reserved.
+*
+*  Redistribution and use in source and binary forms, with or without
+*  modification, are permitted provided that the following conditions
+*  are met:
+*
+*   * Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*   * Redistributions in binary form must reproduce the above
+*     copyright notice, this list of conditions and the following
+*     disclaimer in the documentation and/or other materials provided
+*     with the distribution.
+*   * Neither the name of the Willow Garage nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+*  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+*  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+*  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+*  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+*  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+*  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+*  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+*  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+*  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+*  POSSIBILITY OF SUCH DAMAGE.
+*********************************************************************/
+
+#include <gtest/gtest.h>
+#include "urdf/model.h"
+
+
+TEST(UrdfCompatibility, UpcastSharedPtr)
+{
+  urdf::ModelSharedPtr model(new urdf::Model);
+  model->name_ = "UpcastSharedPtr";
+  urdf::ModelInterfaceSharedPtr interface = model;
+  EXPECT_EQ(std::string("UpcastSharedPtr"), interface->getName());
+}
+
+
+int main(int argc, char** argv)
+{
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
diff --git a/urdf/urdfdom_compatibility.h.in b/urdf/urdfdom_compatibility.h.in
index c355b30d..7ee6cba2 100644
--- a/urdf/urdfdom_compatibility.h.in
+++ b/urdf/urdfdom_compatibility.h.in
@@ -41,7 +41,8 @@
 #define URDFDOM_HEADERS_MINOR_VERSION @URDFDOM_HEADERS_MINOR_VERSION@
 #define URDFDOM_HEADERS_REVISION_VERSION @URDFDOM_HEADERS_REVISION_VERSION@
 
-// for Wily: maintain compatibility between urdfdom 0.3 and 0.4 (definining SharedPtr types)
+// Define shared pointers for urdfdom versions less than 0.4
+// Plus define ModelSharedPtr for 0.4
 #if URDFDOM_HEADERS_MAJOR_VERSION == 0 && URDFDOM_HEADERS_MINOR_VERSION <= 4
 
 #include <boost/shared_ptr.hpp>
@@ -54,6 +55,8 @@ typedef boost::shared_ptr<const Class> Class##ConstSharedPtr; \
 typedef boost::weak_ptr<Class> Class##WeakPtr
 
 namespace urdf {
+// These shared_ptrs were added to urdfdom in 0.4.0,
+// so if urdfdom == 0.4 this is duplicate work
 URDF_TYPEDEF_CLASS_POINTER(Box);
 URDF_TYPEDEF_CLASS_POINTER(Collision);
 URDF_TYPEDEF_CLASS_POINTER(Cylinder);
@@ -74,6 +77,8 @@ URDF_TYPEDEF_CLASS_POINTER(Sphere);
 URDF_TYPEDEF_CLASS_POINTER(Visual);
 
 URDF_TYPEDEF_CLASS_POINTER(ModelInterface);
+
+// ModelSharedPtr is the only one that needs to be defined for urdfdom 0.4
 URDF_TYPEDEF_CLASS_POINTER(Model);
 }
 
@@ -89,6 +94,9 @@ typedef std::shared_ptr<ModelInterface> ModelInterfaceSharedPtr;
 typedef std::shared_ptr<const ModelInterface> ModelInterfaceConstSharedPtr;
 typedef std::weak_ptr<ModelInterface> ModelInterfaceWeakPtr;
 
+// Forward declaration
+class Model;
+
 typedef std::shared_ptr<Model> ModelSharedPtr;
 typedef std::shared_ptr<const Model> ModelConstSharedPtr;
 typedef std::weak_ptr<Model> ModelWeakPtr;