diff --git a/include/wx/gtk/filepicker.h b/include/wx/gtk/filepicker.h
index bb91c6d554..976da2a469 100644
--- a/include/wx/gtk/filepicker.h
+++ b/include/wx/gtk/filepicker.h
@@ -49,7 +49,7 @@
     /* so, override wxButton::GTKGetWindow and return NULL as GTK+ doesn't */ \
     /* give us access to the internal GdkWindow of a GtkFileChooserButton  */ \
 protected:                                                                    \
-    virtual GdkWindow *GTKGetWindow(wxArrayGdkWindows& windows) const         \
+    virtual GdkWindow *GTKGetWindow(wxArrayGdkWindows& WXUNUSED(windows)) const \
         { return NULL; }