diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index f63ad95b6d..cacab0108c 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -511,12 +511,12 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         // long simulateTotalTime = Util.EnvironmentTickCountSubtract(simulateStartTime);
         // return (timeStep * (float)simulateTotalTime);
 
-        // TODO: FIX THIS: fps calculation possibly wrong.
-        // This calculation says 1/timeStep is the ideal frame rate. Any time added to
-        //    that by the physics simulation gives a slower frame rate.
-        long totalSimulationTime = Util.EnvironmentTickCountSubtract(simulateStartTime);
-        if (totalSimulationTime >= timeStep)
-            return 0;
+        // TODO: FIX THIS: fps calculation possibly wrong.
+        // This calculation says 1/timeStep is the ideal frame rate. Any time added to
+        //    that by the physics simulation gives a slower frame rate.
+        long totalSimulationTime = Util.EnvironmentTickCountSubtract(simulateStartTime);
+        if (totalSimulationTime >= timeStep)
+            return 0;
         return 1f / (timeStep + totalSimulationTime);
     }
 
@@ -595,12 +595,6 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         // make sure no stepping happens while we're deleting stuff
         m_initialized = false;
 
-        if (m_constraintCollection != null)
-        {
-            m_constraintCollection.Dispose();
-            m_constraintCollection = null;
-        }
-
         foreach (KeyValuePair<uint, BSCharacter> kvp in m_avatars)
         {
             kvp.Value.Destroy();
@@ -613,6 +607,13 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         }
         m_prims.Clear();
 
+        // Now that the prims are all cleaned up, there should be no constraints left
+        if (m_constraintCollection != null)
+        {
+            m_constraintCollection.Dispose();
+            m_constraintCollection = null;
+        }
+
         // Anything left in the unmanaged code should be cleaned out
         BulletSimAPI.Shutdown(WorldID);