diff --git a/OdeWorld.cc b/OdeWorld.cc
index 38b4aba..daf3e61 100644
--- a/OdeWorld.cc
+++ b/OdeWorld.cc
@@ -4,9 +4,14 @@
 OdeWorld::OdeWorld()
 {
     m_world = dWorldCreate();
+    m_space = dHashSpaceCreate(0);
+    m_contactJointGroup = dJointGroupCreate(0);
+    setGravity(0, -9.81, 0);
 }
 
 OdeWorld::~OdeWorld()
 {
+    dJointGroupDestroy(m_contactJointGroup);
+    dSpaceDestroy(m_space);
     dWorldDestroy(m_world);
 }
diff --git a/OdeWorld.h b/OdeWorld.h
index 055a6d0..f2121c0 100644
--- a/OdeWorld.h
+++ b/OdeWorld.h
@@ -9,9 +9,15 @@ class OdeWorld
     public:
         OdeWorld();
         ~OdeWorld();
+        void setGravity(float x, float y, float z)
+        {
+            dWorldSetGravity(m_world, x, y, z);
+        }
 
     protected:
-        dWorldID    m_world;
+        dWorldID        m_world;
+        dSpaceID        m_space;
+        dJointGroupID   m_contactJointGroup;
 };
 
 #endif