diff --git a/include/haproxy/thread.h b/include/haproxy/thread.h
index c70108b..d55c54e 100644
--- a/include/haproxy/thread.h
+++ b/include/haproxy/thread.h
@@ -88,11 +88,21 @@
 
 #define ha_sigmask(how, set, oldset)  sigprocmask(how, set, oldset)
 
-static inline void ha_set_tid(unsigned int tid)
+/* Sets the current thread to a valid one described by <thr>, or to any thread
+ * and any group if NULL (e.g. for use during boot where they're not totally
+ * initialized).
+ */
+static inline void ha_set_thread(const struct thread_info *thr)
 {
-	ti = &ha_thread_info[tid];
-	tg = ti->tg ? ti->tg : &ha_tgroup_info[0];
-	th_ctx = &ha_thread_ctx[tid];
+	if (thr) {
+		ti = thr;
+		tg = ti->tg;
+		th_ctx = &ha_thread_ctx[ti->tid];
+	} else {
+		ti = &ha_thread_info[0];
+		tg = &ha_tgroup_info[0];
+		th_ctx = &ha_thread_ctx[0];
+	}
 }
 
 static inline void thread_idle_now()
@@ -203,18 +213,28 @@
 
 #define ha_sigmask(how, set, oldset)  pthread_sigmask(how, set, oldset)
 
-/* sets the thread ID, TID bit and thread cfg/ctx pointers for the current
- * thread. Since it may be called during early boot even before threads are
- * initialized, we have to be extra careful about some fields which may still
- * be null. For example tg may be null during a part of the boot.
+/* Sets the current thread to a valid one described by <thr>, or to any thread
+ * and any group if NULL (e.g. for use during boot where they're not totally
+ * initialized).
  */
-static inline void ha_set_tid(unsigned int data)
+static inline void ha_set_thread(const struct thread_info *thr)
 {
-	tid     = data;
-	tid_bit = (1UL << tid);
-	ti      = &ha_thread_info[tid];
-	tg      = ti->tg ? ti->tg : &ha_tgroup_info[0];
-	th_ctx  = &ha_thread_ctx[tid];
+	if (thr) {
+		BUG_ON(!thr->tid_bit);
+		BUG_ON(!thr->tg);
+
+		ti      = thr;
+		tg      = thr->tg;
+		tid     = thr->tid;
+		tid_bit = thr->tid_bit;
+		th_ctx  = &ha_thread_ctx[tid];
+	} else {
+		tid     = 0;
+		tid_bit = 1;
+		ti      = &ha_thread_info[0];
+		tg      = &ha_tgroup_info[0];
+		th_ctx  = &ha_thread_ctx[0];
+	}
 }
 
 /* Marks the thread as idle, which means that not only it's not doing anything
diff --git a/src/haproxy.c b/src/haproxy.c
index c8b5ee7..7a4dc79 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -253,6 +253,7 @@
 /* per-boot randomness */
 unsigned char boot_seed[20];        /* per-boot random seed (160 bits initially) */
 
+/* takes the thread config in argument or NULL for any thread */
 static void *run_thread_poll_loop(void *data);
 
 /* bitfield of a few warnings to emit just once (WARN_*) */
@@ -836,7 +837,7 @@
 		leave */
 
 	fork_poller();
-	run_thread_poll_loop(0);
+	run_thread_poll_loop(NULL);
 }
 
 /*
@@ -2697,7 +2698,7 @@
 	__decl_thread(static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER);
 	__decl_thread(static pthread_cond_t  init_cond  = PTHREAD_COND_INITIALIZER);
 
-	ha_set_tid((unsigned long)data);
+	ha_set_thread(data);
 	set_thread_cpu_affinity();
 	clock_set_local_source();
 
@@ -3397,7 +3398,7 @@
 	haproxy_unblock_signals();
 
 	/* Finally, start the poll loop for the first thread */
-	run_thread_poll_loop(0);
+	run_thread_poll_loop(&ha_thread_info[0]);
 
 	/* wait for all threads to terminate */
 	wait_for_threads_completion();
diff --git a/src/hlua.c b/src/hlua.c
index d5d3f59..b03d8bb 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -11060,7 +11060,7 @@
 
 	/* loading for global state */
 	hlua_state_id = 0;
-	ha_set_tid(0);
+	ha_set_thread(NULL);
 	return hlua_load_state(args[1], hlua_states[0], err);
 }
 
@@ -11104,7 +11104,7 @@
 
 	/* loading for thread 1 only */
 	hlua_state_id = 1;
-	ha_set_tid(0);
+	ha_set_thread(NULL);
 	return hlua_load_state(args[1], hlua_states[1], err);
 }
 
@@ -11311,7 +11311,7 @@
 
 	/* Perform post init of common thread */
 	hlua_state_id = 0;
-	ha_set_tid(0);
+	ha_set_thread(&ha_thread_info[0]);
 	ret = hlua_post_init_state(hlua_states[hlua_state_id]);
 	if (ret == 0)
 		return 0;
@@ -11320,7 +11320,7 @@
 	for (hlua_state_id = 2; hlua_state_id < global.nbthread + 1; hlua_state_id++) {
 
 		/* set thread context */
-		ha_set_tid(hlua_state_id - 1);
+		ha_set_thread(&ha_thread_info[hlua_state_id - 1]);
 
 		/* Init lua state */
 		hlua_states[hlua_state_id] = hlua_init_state(hlua_state_id);
@@ -11336,13 +11336,13 @@
 	}
 
 	/* Reset thread context */
-	ha_set_tid(0);
+	ha_set_thread(NULL);
 
 	/* Execute post init for all states */
 	for (hlua_state_id = 1; hlua_state_id < global.nbthread + 1; hlua_state_id++) {
 
 		/* set thread context */
-		ha_set_tid(hlua_state_id - 1);
+		ha_set_thread(&ha_thread_info[hlua_state_id - 1]);
 
 		/* run post init */
 		ret = hlua_post_init_state(hlua_states[hlua_state_id]);
@@ -11351,7 +11351,7 @@
 	}
 
 	/* Reset thread context */
-	ha_set_tid(0);
+	ha_set_thread(NULL);
 
 	/* control functions registering. Each function must have:
 	 *  - only the function_ref[0] set positive and all other to -1
@@ -12057,12 +12057,12 @@
 
 	/* Init state for common/shared lua parts */
 	hlua_state_id = 0;
-	ha_set_tid(0);
+	ha_set_thread(NULL);
 	hlua_states[0] = hlua_init_state(0);
 
 	/* Init state 1 for thread 0. We have at least one thread. */
 	hlua_state_id = 1;
-	ha_set_tid(0);
+	ha_set_thread(NULL);
 	hlua_states[1] = hlua_init_state(1);
 
 	/* Proxy and server configuration initialisation. */
diff --git a/src/thread.c b/src/thread.c
index 2f904de..ce6a476 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -217,7 +217,7 @@
 	/* Create nbthread-1 thread. The first thread is the current process */
 	ha_pthread[0] = pthread_self();
 	for (i = 1; i < global.nbthread; i++)
-		pthread_create(&ha_pthread[i], NULL, handler, (void *)(long)i);
+		pthread_create(&ha_pthread[i], NULL, handler, &ha_thread_info[i]);
 }
 
 /* waits for all threads to terminate. Does nothing when threads are