diff --git a/servers/vfs/const.h b/servers/vfs/const.h
index 6c0ef4805..3c0671e83 100644
--- a/servers/vfs/const.h
+++ b/servers/vfs/const.h
@@ -44,6 +44,7 @@
 #define XLOCK   (-NR_TASKS-2)	/* used in fp_task when susp'd on lock */
 #define XPOPEN  (-NR_TASKS-3)	/* used in fp_task when susp'd on pipe open */
 #define XSELECT (-NR_TASKS-4)	/* used in fp_task when susp'd on select */
+#define XDOPEN  (-NR_TASKS-5)	/* used in fp_task when susp'd on device open */
 
 #define NO_BIT   ((bit_t) 0)	/* returned by alloc_bit() to signal failure */