diff --git a/include/proto/mworker.h b/include/proto/mworker.h
index 86f09049f..2386a445a 100644
--- a/include/proto/mworker.h
+++ b/include/proto/mworker.h
@@ -27,7 +27,6 @@ void mworker_catch_sigterm(struct sig_handler *sh);
 void mworker_catch_sigchld(struct sig_handler *sh);
 
 void mworker_accept_wrapper(int fd);
-void mworker_pipe_register();
 
 void mworker_cleanlisteners();
 
diff --git a/src/haproxy.c b/src/haproxy.c
index 2b3cf2ebf..661cbd1c1 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -2495,7 +2495,6 @@ static void *run_thread_poll_loop(void *data)
 {
 	struct per_thread_init_fct   *ptif;
 	struct per_thread_deinit_fct *ptdf;
-	__decl_hathreads(static HA_SPINLOCK_T start_lock);
 
 	ha_set_tid((unsigned long)data);
 	tv_update_date(-1,-1);
@@ -2511,12 +2510,6 @@ static void *run_thread_poll_loop(void *data)
 		}
 	}
 
-	if ((global.mode & MODE_MWORKER) && master == 0) {
-		HA_SPIN_LOCK(START_LOCK, &start_lock);
-		mworker_pipe_register();
-		HA_SPIN_UNLOCK(START_LOCK, &start_lock);
-	}
-
 	/* broadcast that we are ready and wait for other threads to finish
 	 * their initialization.
 	 */
diff --git a/src/mworker.c b/src/mworker.c
index cac74102c..d5040b759 100644
--- a/src/mworker.c
+++ b/src/mworker.c
@@ -357,22 +357,29 @@ void mworker_accept_wrapper(int fd)
 }
 
 /*
- * This function register the accept wrapper for the sockpair of the master worker
+ * This function registers the accept wrapper for the sockpair of the master
+ * worker. It's only handled by worker thread #0. Other threads and master do
+ * nothing here. It always returns 1 (success).
  */
-void mworker_pipe_register()
+static int mworker_pipe_register_per_thread()
 {
-	/* The iocb should be already initialized with listener_accept */
-	if (fdtab[proc_self->ipc_fd[1]].iocb == mworker_accept_wrapper)
-		return;
+	if (!(global.mode & MODE_MWORKER) || master)
+		return 1;
+
+	if (tid != 0)
+		return 1;
 
 	fcntl(proc_self->ipc_fd[1], F_SETFL, O_NONBLOCK);
 	/* In multi-tread, we need only one thread to process
 	 * events on the pipe with master
 	 */
-	fd_insert(proc_self->ipc_fd[1], fdtab[proc_self->ipc_fd[1]].owner, mworker_accept_wrapper, 1);
+	fd_insert(proc_self->ipc_fd[1], fdtab[proc_self->ipc_fd[1]].owner, mworker_accept_wrapper, tid_bit);
 	fd_want_recv(proc_self->ipc_fd[1]);
+	return 1;
 }
 
+REGISTER_PER_THREAD_INIT(mworker_pipe_register_per_thread);
+
 /* ----- proxies ----- */
 /*
  * Upon a reload, the master worker needs to close all listeners FDs but the mworker_pipe