diff --git a/include/wx/osx/filedlg.h b/include/wx/osx/filedlg.h
index 5ddc524e76..170795379e 100644
--- a/include/wx/osx/filedlg.h
+++ b/include/wx/osx/filedlg.h
@@ -70,6 +70,7 @@ protected:
     
 #if wxOSX_USE_COCOA
     virtual wxWindow* CreateFilterPanel(wxWindow *extracontrol);
+    void DoOnFilterSelected(int index);
     virtual void OnFilterSelected(wxCommandEvent &event);
 
     wxArrayString m_filterExtensions;
diff --git a/src/osx/cocoa/filedlg.mm b/src/osx/cocoa/filedlg.mm
index 1aa5828bda..c0b6185d34 100644
--- a/src/osx/cocoa/filedlg.mm
+++ b/src/osx/cocoa/filedlg.mm
@@ -381,11 +381,8 @@ wxWindow* wxFileDialog::CreateFilterPanel(wxWindow *extracontrol)
     return extrapanel;
 }
 
-// An item has been selected in the file filter wxChoice:
-void wxFileDialog::OnFilterSelected( wxCommandEvent &WXUNUSED(event) )
+void wxFileDialog::DoOnFilterSelected(int index)
 {
-    int index = m_filterChoice->GetSelection();
-
     NSArray* types = GetTypesFromExtension(m_filterExtensions[index],m_currentExtensions);
     NSSavePanel* panel = (NSSavePanel*) GetWXWindow();
     if ( m_delegate )
@@ -394,6 +391,12 @@ void wxFileDialog::OnFilterSelected( wxCommandEvent &WXUNUSED(event) )
         [panel setAllowedFileTypes:types];
 }
 
+// An item has been selected in the file filter wxChoice:
+void wxFileDialog::OnFilterSelected( wxCommandEvent &WXUNUSED(event) )
+{
+    DoOnFilterSelected( m_filterChoice->GetSelection() );
+}
+
 bool wxFileDialog::CheckFile( const wxString& filename )
 {
     if ( m_currentExtensions.GetCount() == 0 )
@@ -548,6 +551,19 @@ int wxFileDialog::ShowModal()
         {
         }
 
+        /*
+        Let the file dialog know what file type should be used initially.
+        If this is not done then when setting the filter index
+        programmatically to 1 the file will still have the extension
+        of the first file type instead of the second one. E.g. when file
+        types are foo and bar, a filename "myletter" with SetDialogIndex(1)
+        would result in saving as myletter.foo, while we want myletter.bar.
+        */
+        if(m_firstFileTypeFilter > 0)
+        {
+            DoOnFilterSelected(m_firstFileTypeFilter);
+        }
+
         returnCode = [sPanel runModalForDirectory:dir.AsNSString() file:file.AsNSString() ];
         ModalFinishedCallback(sPanel, returnCode);
     }