diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp
index 1a668976f3..30f9bca117 100644
--- a/src/msw/thread.cpp
+++ b/src/msw/thread.cpp
@@ -761,7 +761,8 @@ wxThreadInternal::WaitForTerminate(wxCriticalSection& cs,
         Cancel();
     }
 
-    threadToDelete->OnDelete();
+    if ( threadToDelete )
+        threadToDelete->OnDelete();
 
     // now wait for thread to finish
     if ( wxThread::IsMain() )