Index: VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/Makefile.kmk
===================================================================
--- VirtualBox-5.2.0.orig/src/VBox/Additions/x11/vboxvideo/Makefile.kmk
+++ VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/Makefile.kmk
@@ -23,6 +23,9 @@ vboxvideo_70_DEFS := \
 ifeq ($(KBUILD_TARGET),solaris) # don't use .solaris or anything here.
  vboxvideo_70_DEFS += __EXTENSIONS__  ## @todo Why this?
 endif
+if1of ($(KBUILD_TARGET), linux)
+ vboxvideo_70_DEFS += _POSIX_SOURCE ## X requires POSIX extensions
+endif
 vboxvideo_13_DEFS := $(vboxvideo_70_DEFS) VBOXVIDEO_13
 vboxvideo_15_DEFS := \
 	$(vboxvideo_13_DEFS) NO_ANSIC PCIACCESS XSERVER_LIBPCIACCESS _XORG_SERVER_H_ _DIX_CONFIG_H_
Index: VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/edid.c
===================================================================
--- VirtualBox-5.2.0.orig/src/VBox/Additions/x11/vboxvideo/edid.c
+++ VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/edid.c
@@ -36,10 +36,6 @@
  *    Michael Thayer <michael.thayer@oracle.com>
  */
 
-#if XORG_VERSION_CURRENT >= 11900000
-#include <bits/sigset.h>
-typedef __sigset_t sigset_t;
-#endif
 #include "misc.h"
 #include "xf86DDC.h"
 #include "xf86Crtc.h"
Index: VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/pointer.c
===================================================================
--- VirtualBox-5.2.0.orig/src/VBox/Additions/x11/vboxvideo/pointer.c
+++ VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/pointer.c
@@ -36,10 +36,6 @@
 #include "cursorstr.h"
 #include "servermd.h"
 
-#if XORG_VERSION_CURRENT >= 11900000
-#include <bits/sigset.h>
-typedef __sigset_t sigset_t;
-#endif
 #include "vboxvideo.h"
 
 #ifdef XORG_7X
Index: VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/vboxvideo.h
===================================================================
--- VirtualBox-5.2.0.orig/src/VBox/Additions/x11/vboxvideo/vboxvideo.h
+++ VirtualBox-5.2.0/src/VBox/Additions/x11/vboxvideo/vboxvideo.h
@@ -42,8 +42,8 @@
 #ifndef _VBOXVIDEO_H_
 #define _VBOXVIDEO_H_
 
-#include <VBoxVideoGuest.h>
-#include <VBoxVideo.h>
+#include <VBox/Graphics/VBoxVideoGuest.h>
+#include <VBox/Graphics/VBoxVideo.h>
 #include "version-generated.h"
 
 #define VBOX_VENDORID 0x80EE