Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIFrameBuffer.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIFrameBuffer.cpp	(revision 58881)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIFrameBuffer.cpp	(revision 58882)
@@ -64,4 +64,7 @@
 # include <QX11Info>
 # include <X11/Xlib.h>
+# if QT_VERSION >= 0x050000
+#  undef Bool // Qt5 vs Xlib gift..
+# endif /* QT_VERSION >= 0x050000 */
 #endif /* Q_WS_X11 */