diff --git a/src/libCom/osi/osiThread.h b/src/libCom/osi/osiThread.h
index 75e2ecd46..48a994c7e 100644
--- a/src/libCom/osi/osiThread.h
+++ b/src/libCom/osi/osiThread.h
@@ -126,6 +126,9 @@ private:
     epicsEvent begin;
     bool cancel;
 
+    osiThread ( const osiThread & );
+    osiThread & operator = ( const osiThread & );
+
     friend void osiThreadCallEntryPoint (void *pPvt);
 };