diff --git a/include/wx/msw/combo.h b/include/wx/msw/combo.h
index cc9b35d53e..78ef4f59ef 100644
--- a/include/wx/msw/combo.h
+++ b/include/wx/msw/combo.h
@@ -73,10 +73,13 @@ public:
     static int GetFeatures() { return wxComboCtrlFeatures::All; }
 
 #if wxUSE_COMBOCTRL_POPUP_ANIMATION
-    void OnTimerEvent( wxTimerEvent& event );
+    void OnTimerEvent(wxTimerEvent& WXUNUSED(event)) { DoTimerEvent(); }
+
 protected:
+    void DoTimerEvent();
+
     virtual bool AnimateShow( const wxRect& rect, int flags );
-#endif
+#endif // wxUSE_COMBOCTRL_POPUP_ANIMATION
 
 protected:
 
diff --git a/src/msw/combo.cpp b/src/msw/combo.cpp
index caf2fc428e..a37257ae65 100644
--- a/src/msw/combo.cpp
+++ b/src/msw/combo.cpp
@@ -763,7 +763,7 @@ static wxUint32 GetUserPreferencesMask()
 #endif
 
 #if wxUSE_COMBOCTRL_POPUP_ANIMATION
-void wxComboCtrl::OnTimerEvent( wxTimerEvent& WXUNUSED(event) )
+void wxComboCtrl::DoTimerEvent()
 {
     bool stopTimer = false;
 
@@ -831,7 +831,7 @@ bool wxComboCtrl::AnimateShow( const wxRect& rect, int flags )
         m_animTimer.SetOwner( this, wxID_ANY );
         m_animTimer.Start( COMBOBOX_ANIMATION_RESOLUTION, wxTIMER_CONTINUOUS );
 
-        OnTimerEvent(*(NULL));  // Event is never used, so we can give NULL
+        DoTimerEvent();
 
         return false;
     }