diff --git a/include/wx/gtk/window.h b/include/wx/gtk/window.h
index 5af2602f75..c8a7729c8e 100644
--- a/include/wx/gtk/window.h
+++ b/include/wx/gtk/window.h
@@ -18,6 +18,13 @@ struct wxGtkIMData;
 
 WX_DEFINE_EXPORTED_ARRAY_PTR(GdkWindow *, wxArrayGdkWindows);
 
+extern "C"
+{
+
+typedef void (*wxGTKCallback)();
+
+}
+
 //-----------------------------------------------------------------------------
 // wxWindowGTK
 //-----------------------------------------------------------------------------
@@ -374,7 +381,7 @@ protected:
     //
     // This is just a wrapper for g_signal_connect() and returns the handler id
     // just as it does.
-    unsigned long GTKConnectWidget(const char *signal, void (*callback)());
+    unsigned long GTKConnectWidget(const char *signal, wxGTKCallback callback);
 
     // Return true from here if PostCreation() should connect to size_request
     // signal: this is done by default but doesn't work for some native
diff --git a/src/gtk/window.cpp b/src/gtk/window.cpp
index 20ddddd5bb..ec6db0f73a 100644
--- a/src/gtk/window.cpp
+++ b/src/gtk/window.cpp
@@ -2444,7 +2444,8 @@ void wxWindowGTK::PostCreation()
         gtk_widget_show( m_widget );
 }
 
-unsigned long wxWindowGTK::GTKConnectWidget(const char *signal, void (*callback)())
+unsigned long
+wxWindowGTK::GTKConnectWidget(const char *signal, wxGTKCallback callback)
 {
     return g_signal_connect(m_widget, signal, callback, this);
 }