diff --git a/src/osgViewer/ViewerBase.cpp b/src/osgViewer/ViewerBase.cpp
index 4b72f5c20..f5b325895 100644
--- a/src/osgViewer/ViewerBase.cpp
+++ b/src/osgViewer/ViewerBase.cpp
@@ -205,11 +205,13 @@ void ViewerBase::setThreadingModel(ThreadingModel threadingModel)
 {
     if (_threadingModel == threadingModel) return;
 
+    bool needSetUpThreading = _threadsRunning;
+
     if (_threadsRunning) stopThreading();
 
     _threadingModel = threadingModel;
 
-    setUpThreading();
+    if (needSetUpThreading) setUpThreading();
 }
 
 ViewerBase::ThreadingModel ViewerBase::suggestBestThreadingModel()