diff --git a/include/wx/gtk/bmpbuttn.h b/include/wx/gtk/bmpbuttn.h
index 473991447b..f4d71460df 100644
--- a/include/wx/gtk/bmpbuttn.h
+++ b/include/wx/gtk/bmpbuttn.h
@@ -68,6 +68,7 @@ public:
 
 protected:
     virtual void OnSetBitmap();
+    virtual wxSize DoGetBestSize() const;
 
     void Init();
 
diff --git a/include/wx/gtk1/bmpbuttn.h b/include/wx/gtk1/bmpbuttn.h
index 473991447b..f4d71460df 100644
--- a/include/wx/gtk1/bmpbuttn.h
+++ b/include/wx/gtk1/bmpbuttn.h
@@ -68,6 +68,7 @@ public:
 
 protected:
     virtual void OnSetBitmap();
+    virtual wxSize DoGetBestSize() const;
 
     void Init();
 
diff --git a/src/gtk/bmpbuttn.cpp b/src/gtk/bmpbuttn.cpp
index 7b51da0f9d..b209fabcc5 100644
--- a/src/gtk/bmpbuttn.cpp
+++ b/src/gtk/bmpbuttn.cpp
@@ -263,6 +263,11 @@ void wxBitmapButton::OnSetBitmap()
     }
 }
 
+wxSize wxBitmapButton::DoGetBestSize() const
+{
+    return wxControl::DoGetBestSize();
+}
+
 bool wxBitmapButton::Enable( bool enable )
 {
     if ( !wxWindow::Enable(enable) )
diff --git a/src/gtk1/bmpbuttn.cpp b/src/gtk1/bmpbuttn.cpp
index 7b51da0f9d..b209fabcc5 100644
--- a/src/gtk1/bmpbuttn.cpp
+++ b/src/gtk1/bmpbuttn.cpp
@@ -263,6 +263,11 @@ void wxBitmapButton::OnSetBitmap()
     }
 }
 
+wxSize wxBitmapButton::DoGetBestSize() const
+{
+    return wxControl::DoGetBestSize();
+}
+
 bool wxBitmapButton::Enable( bool enable )
 {
     if ( !wxWindow::Enable(enable) )