diff --git a/include/wx/frame.h b/include/wx/frame.h
index bd7cc361d6..9b857d9f4b 100644
--- a/include/wx/frame.h
+++ b/include/wx/frame.h
@@ -78,10 +78,7 @@ public:
 
     // sends a size event to the window using its current size -- this has an
     // effect of refreshing the window layout
-    //
-    // currently it is only implemented under MSW but is declared here to make
-    // it possible to call it in portable code without using #ifdef's
-    virtual void SendSizeEvent() { }
+    virtual void SendSizeEvent();
 
     // menu bar functions
     // ------------------
diff --git a/src/common/framecmn.cpp b/src/common/framecmn.cpp
index bdd5dc26d1..0020580068 100644
--- a/src/common/framecmn.cpp
+++ b/src/common/framecmn.cpp
@@ -176,6 +176,15 @@ wxPoint wxFrameBase::GetClientAreaOrigin() const
     return pt;
 }
 
+
+void wxFrameBase::SendSizeEvent()
+{
+    wxSizeEvent event( GetSize(), GetId() );
+    event.SetEventObject( this );
+    GetEventHandler()->AddPendingEvent( event );
+}
+
+
 // ----------------------------------------------------------------------------
 // misc
 // ----------------------------------------------------------------------------