diff --git a/include/wx/msw/clipbrd.h b/include/wx/msw/clipbrd.h
index 7d8b873c11..8432b0f067 100644
--- a/include/wx/msw/clipbrd.h
+++ b/include/wx/msw/clipbrd.h
@@ -52,7 +52,7 @@ WXDLLEXPORT bool wxGetClipboardFormatName(wxDataFormat dataFormat,
 //-----------------------------------------------------------------------------
 
 class WXDLLEXPORT wxDataObject;
-class WXDLLEXPORT wxClipboard : public wxObject
+class WXDLLEXPORT wxClipboard : public wxClipboardBase
 {
     DECLARE_DYNAMIC_CLASS(wxClipboard)
 
@@ -76,7 +76,7 @@ public:
     virtual bool AddData( wxDataObject *data );
 
     // ask if data in correct format is available
-    virtual bool IsSupported( wxDataFormat format );
+    virtual bool IsSupported( const wxDataFormat& format );
 
     // fill data with data on the clipboard (if available)
     virtual bool GetData( wxDataObject& data );
diff --git a/include/wx/os2/clipbrd.h b/include/wx/os2/clipbrd.h
index ab3c933eb9..2db04c431a 100644
--- a/include/wx/os2/clipbrd.h
+++ b/include/wx/os2/clipbrd.h
@@ -51,7 +51,7 @@ WXDLLEXPORT bool wxGetClipboardFormatName(wxDataFormat dataFormat,
 //-----------------------------------------------------------------------------
 
 class WXDLLEXPORT wxDataObject;
-class WXDLLEXPORT wxClipboard : public wxObject
+class WXDLLEXPORT wxClipboard : public wxClipboardBase
 {
     DECLARE_DYNAMIC_CLASS(wxClipboard)
 
@@ -75,7 +75,7 @@ public:
     virtual bool AddData( wxDataObject *data );
 
     // ask if data in correct format is available
-    virtual bool IsSupported( wxDataFormat format );
+    virtual bool IsSupported( const wxDataFormat& format );
 
     // fill data with data on the clipboard (if available)
     virtual bool GetData( wxDataObject& data );
diff --git a/src/msw/clipbrd.cpp b/src/msw/clipbrd.cpp
index c3ed1b194b..9d35124765 100644
--- a/src/msw/clipbrd.cpp
+++ b/src/msw/clipbrd.cpp
@@ -701,7 +701,7 @@ void wxClipboard::Close()
 #endif
 }
 
-bool wxClipboard::IsSupported( wxDataFormat format )
+bool wxClipboard::IsSupported( const wxDataFormat& format )
 {
     return wxIsClipboardFormatAvailable(format);
 }
diff --git a/src/os2/clipbrd.cpp b/src/os2/clipbrd.cpp
index e27f3bc58a..efb52d4ea3 100644
--- a/src/os2/clipbrd.cpp
+++ b/src/os2/clipbrd.cpp
@@ -532,7 +532,7 @@ void wxClipboard::Close()
     wxCloseClipboard();
 }
 
-bool wxClipboard::IsSupported( wxDataFormat format )
+bool wxClipboard::IsSupported( const wxDataFormat& format )
 {
     return wxIsClipboardFormatAvailable(format);
 }