diff --git a/src/pv/pvData.h b/src/pv/pvData.h
index a33fb0eb..11bf93fd 100644
--- a/src/pv/pvData.h
+++ b/src/pv/pvData.h
@@ -513,6 +513,10 @@ typedef std::tr1::shared_ptr<PVULong> PVULongPtr;
 typedef std::tr1::shared_ptr<PVFloat> PVFloatPtr;
 typedef std::tr1::shared_ptr<PVDouble> PVDoublePtr;
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable:4250)
+#endif
 /**
  * @brief PVString is special case, since it implements SerializableArray
  *
@@ -538,6 +542,9 @@ class epicsShareClass PVString : public PVScalarValue<std::string>, Serializable
     EPICS_NOT_COPYABLE(PVString)
 };
 typedef std::tr1::shared_ptr<PVString> PVStringPtr;
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
 
 
 /**