--- gpsim-0.29.0/modules/logic.cc
+++ gpsim-0.29.0/modules/logic.cc
@@ -269,8 +269,10 @@
 
 LogicGate::~LogicGate()
 {
+#ifdef HAVE_GUI
   if (pixbuf)
     g_object_unref(pixbuf);
+#endif
 }
 
 //--------------------------------------------------------------