diff --git a/OpenSim/Region/Environment/Scenes/ScenePresence.cs b/OpenSim/Region/Environment/Scenes/ScenePresence.cs
index 2215850e5d..ec3137f8a5 100644
--- a/OpenSim/Region/Environment/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Environment/Scenes/ScenePresence.cs
@@ -594,7 +594,7 @@ namespace OpenSim.Region.Environment.Scenes
             m_isChildAgent = false;
             float posZLimit = (float)m_scene.GetLandHeight((int)pos.X, (int)pos.Y);
             float newPosZ = posZLimit + m_avHeight;
-            if (posZLimit >= (pos.Z -(m_avHeight/2)) && !(Single.IsInfinity(newPosZ) && Single.IsNaN(newPosZ)))
+            if (posZLimit >= (pos.Z -(m_avHeight/2)) && !(Single.IsInfinity(newPosZ) || Single.IsNaN(newPosZ)))
             {
                 pos.Z = newPosZ;
             }