diff --git a/components/detournavigator/navigatorimpl.cpp b/components/detournavigator/navigatorimpl.cpp
index c47cf97662..142ba590d2 100644
--- a/components/detournavigator/navigatorimpl.cpp
+++ b/components/detournavigator/navigatorimpl.cpp
@@ -18,6 +18,8 @@ namespace DetourNavigator
 
     void NavigatorImpl::addAgent(const osg::Vec3f& agentHalfExtents)
     {
+        if(agentHalfExtents.length2() <= 0)
+            return;
         ++mAgents[agentHalfExtents];
         mNavMeshManager.addAgent(agentHalfExtents);
     }