--- src/VBox/Additions/linux/drm/vboxvideo_drm.c.orig	2015-02-22 14:30:54.000000000 +0100
+++ src/VBox/Additions/linux/drm/vboxvideo_drm.c	2015-02-22 14:31:43.000000000 +0100
@@ -126,7 +126,12 @@
         .open = drm_open,
         .release = drm_release,
         .unlocked_ioctl = drm_ioctl,
-        .mmap = drm_mmap,
+# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0)
+	 /* This shouldn't be necessary even for old kernels as there is
+	 * nothing sensible to mmap. But we play safe and keep it for
+	 * legacy reasons. */
+	.mmap = drm_mmap,
+# endif
         .poll = drm_poll,
 };
 #endif