diff --git a/src/libCom/cxxTemplates/epicsSingleton.h b/src/libCom/cxxTemplates/epicsSingleton.h
index ab18cd970..0e1d0f9db 100644
--- a/src/libCom/cxxTemplates/epicsSingleton.h
+++ b/src/libCom/cxxTemplates/epicsSingleton.h
@@ -24,6 +24,7 @@
 #include "epicsMutex.h"
 #include "epicsGuard.h"
 #include "epicsThread.h"
+#include "epicsAssert.h"
 #include "compilerDependencies.h"
 
 // This class exists for the purpose of avoiding file scope
@@ -103,6 +104,20 @@ inline epicsSingleton<TYPE>::~epicsSingleton ()
     // sorts of problems then clean up is left to other classes.
 }
 
+// SUN PRO generates warnings unless it sees an implementation
+#ifdef _SUNPRO_C
+    template < class TYPE >
+    inline epicsSingleton<TYPE>::epicsSingleton ( const epicsSingleton & )
+    {
+        assert ( 0 );
+    }
+    template < class TYPE >
+    inline epicsSingleton & epicsSingleton<TYPE>::operator = ( const epicsSingleton & )
+    {
+        assert ( 0 );
+    }
+#endif
+
 epicsShareFunc epicsMutex & epicsSingletonPrivateMutex ();
 
 // borland 5.5 is unable to build this function optimized if it is inline