diff --git a/src/client/pv/pvAccess.h b/src/client/pv/pvAccess.h
index fa0028d..6cd4326 100644
--- a/src/client/pv/pvAccess.h
+++ b/src/client/pv/pvAccess.h
@@ -1366,6 +1366,8 @@ public:
 
     typedef std::vector<std::string> stringVector_t;
 
+    virtual ~ChannelProviderRegistry() {}
+
 
     //! Create a custom registry
     static ChannelProviderRegistry::shared_pointer build();
diff --git a/src/client/pva/client.h b/src/client/pva/client.h
index b5051db..2d2ccff 100644
--- a/src/client/pva/client.h
+++ b/src/client/pva/client.h
@@ -193,8 +193,10 @@ void registerRefTrack();
  */
 class epicsShareClass ClientChannel
 {
+#if defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 305)
 public:
-    // public only as a workaround for old gcc
+    // Impl is public only as a workaround on older GCC
+#endif
     struct Impl;
 private:
     std::tr1::shared_ptr<Impl> impl;