diff --git a/include/proto/fd.h b/include/proto/fd.h
index e47d8fd5f..465d6601a 100644
--- a/include/proto/fd.h
+++ b/include/proto/fd.h
@@ -404,6 +404,7 @@ static inline void fd_insert(int fd)
 	fdtab[fd].linger_risk = 0;
 	fdtab[fd].cloned = 0;
 	fdtab[fd].cache = 0;
+	fdtab[fd].process_mask = 0; // unused for now
 	SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);
 
 	SPIN_LOCK(FDTAB_LOCK, &fdtab_lock);
diff --git a/include/types/fd.h b/include/types/fd.h
index 7042dab11..e196aec98 100644
--- a/include/types/fd.h
+++ b/include/types/fd.h
@@ -94,6 +94,7 @@ enum fd_states {
 struct fdtab {
 	void (*iocb)(int fd);                /* I/O handler */
 	void *owner;                         /* the connection or listener associated with this fd, NULL if closed */
+	unsigned long process_mask;          /* mask of thread IDs authorized to process the task */
 #ifdef USE_THREAD
 	HA_SPINLOCK_T lock;
 #endif
diff --git a/src/fd.c b/src/fd.c
index 6c53a3b28..262127851 100644
--- a/src/fd.c
+++ b/src/fd.c
@@ -202,6 +202,7 @@ static void fd_dodelete(int fd, int do_close)
 	fdtab[fd].owner = NULL;
 	fdtab[fd].updated = 0;
 	fdtab[fd].new = 0;
+	fdtab[fd].process_mask = 0;
 	if (do_close)
 		close(fd);
 	SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);