--- gr_UnixCairoGraphics.cpp.orig	2017-06-06 17:54:57.782535095 +0000
+++ gr_UnixCairoGraphics.cpp	2017-06-06 17:55:14.590257997 +0000
@@ -180,7 +180,7 @@
 	if (m_styleBg) {
 		g_object_unref(m_styleBg);
 	}
-	m_styleBg = XAP_GtkStyle_get_style(nullptr, "GtkButton"); // "button"
+	m_styleBg = XAP_GtkStyle_get_style(0, "GtkButton"); // "button"
 	// guess colours
 	// WHITE
 	GdkRGBA rgba2;
@@ -627,7 +627,7 @@
 		_setProps();
 		cairo_save (m_cr);
 
-		GtkStyleContext *context = nullptr;
+		GtkStyleContext *context = 0;
 		switch(c) {
 		case GR_Graphics::CLR3D_Background:
 			context = m_styleBg;