diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 2b954ad..ffd8ad92 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -150,6 +150,7 @@
 #define DRIVER_BUS_PCI 0x1
 #define DRIVER_BUS_PLATFORM 0x2
 #define DRIVER_BUS_USB 0x3
+#define DRIVER_BUS_HOST1X 0x4
 
 /***********************************************************************/
 /** \name Begin the DRM... */