--- gtk-qt-engine.orig/src/qt_theme_draw.c
+++ gtk-qt-engine/src/qt_theme_draw.c
@@ -19,6 +19,7 @@
  ***************************************************************************/
 
 #include <math.h>
+#include <stdlib.h>
 #include <string.h>
 #include <gtk/gtkprogressbar.h>
 #include <gdk/gdk.h>