diff --git a/src/fd.c b/src/fd.c
index b3ae2c40b..f206d2a62 100644
--- a/src/fd.c
+++ b/src/fd.c
@@ -328,6 +328,10 @@ void _fd_delete_orphan(int fd)
 	_HA_ATOMIC_SUB(&ha_used_fds, 1);
 }
 
+#ifndef HA_HAVE_CAS_DW
+__decl_thread(__decl_rwlock(fd_mig_lock));
+#endif
+
 /* Deletes an FD from the fdsets. The file descriptor is also closed, possibly
  * asynchronously. Only the owning thread may do this.
  */
@@ -350,15 +354,17 @@ void fd_delete(int fd)
 	 */
 
 	HA_ATOMIC_OR(&fdtab[fd].running_mask, tid_bit);
+#ifndef HA_HAVE_CAS_DW
+	HA_RWLOCK_WRLOCK(OTHER_LOCK, &fd_mig_lock);
+#endif
 	HA_ATOMIC_STORE(&fdtab[fd].thread_mask, 0);
+#ifndef HA_HAVE_CAS_DW
+	HA_RWLOCK_WRUNLOCK(OTHER_LOCK, &fd_mig_lock);
+#endif
 	if (fd_clr_running(fd) == 0)
 		_fd_delete_orphan(fd);
 }
 
-#ifndef HA_HAVE_CAS_DW
-__decl_thread(__decl_rwlock(fd_mig_lock));
-#endif
-
 /*
  * Take over a FD belonging to another thread.
  * unexpected_conn is the expected owner of the fd.