diff --git a/include/haproxy/tinfo.h b/include/haproxy/tinfo.h
index 4bae4f2b3..3d10560f9 100644
--- a/include/haproxy/tinfo.h
+++ b/include/haproxy/tinfo.h
@@ -68,33 +68,36 @@ static inline int thread_set_is_empty(const struct thread_set *ts)
 	return 1;
 }
 
-/* returns the number starting at 1 of the first thread-group set in thread set
+/* returns the number starting at 1 of the <n>th thread-group set in thread set
  * <ts>, or zero if the set is empty or if thread numbers are only absolute.
+ * <n> starts at zero and corresponds to the number of non-empty groups to be
+ * skipped (i.e. 0 returns the first one).
  */
-static inline int thread_set_first_group(const struct thread_set *ts)
+static inline int thread_set_nth_group(const struct thread_set *ts, int n)
 {
 	int i;
 
 	if (ts->nbgrp) {
 		for (i = 0; i < MAX_TGROUPS; i++)
-			if (ts->rel[i])
+			if (ts->rel[i] && !n--)
 				return i + 1;
 	}
 	return 0;
 }
 
-/* returns the thread mask of the first assigned thread-group in the thread
+/* returns the thread mask of the <n>th assigned thread-group in the thread
  * set <ts> for relative sets, the first thread mask at all in case of absolute
  * sets, or zero if the set is empty. This is only used temporarily to ease the
- * transition.
+ * transition. <n> starts at zero and corresponds to the number of non-empty
+ * groups to be skipped (i.e. 0 returns the first one).
  */
-static inline ulong thread_set_first_tmask(const struct thread_set *ts)
+static inline ulong thread_set_nth_tmask(const struct thread_set *ts, int n)
 {
 	int i;
 
 	if (ts->nbgrp) {
 		for (i = 0; i < MAX_TGROUPS; i++)
-			if (ts->rel[i])
+			if (ts->rel[i] && !n--)
 				return ts->rel[i];
 	}
 	return ts->abs[0];
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 06ee98097..52f40d633 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -3016,8 +3016,8 @@ init_proxies_list_stage1:
 					}
 
 					/* assign the first (and only) thread and group */
-					new_li->rx.bind_thread = thread_set_first_tmask(&new_ts);
-					new_li->rx.bind_tgroup = thread_set_first_group(&new_ts);
+					new_li->rx.bind_thread = thread_set_nth_tmask(&new_ts, 0);
+					new_li->rx.bind_tgroup = thread_set_nth_group(&new_ts, 0);
 					done -= todo;
 
 					shard++;
@@ -4458,8 +4458,8 @@ init_proxies_list_stage2:
 
 					/* apply thread masks and groups to all receivers */
 					list_for_each_entry(li, &bind_conf->listeners, by_bind) {
-						li->rx.bind_thread = thread_set_first_tmask(&bind_conf->thread_set);
-						li->rx.bind_tgroup = thread_set_first_group(&bind_conf->thread_set);
+						li->rx.bind_thread = thread_set_nth_tmask(&bind_conf->thread_set, 0);
+						li->rx.bind_tgroup = thread_set_nth_group(&bind_conf->thread_set, 0);
 					}
 
 					if (bind_conf->xprt->prepare_bind_conf &&
diff --git a/src/thread.c b/src/thread.c
index 0deb9202b..af27bbb60 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -1311,7 +1311,7 @@ int thread_resolve_group_mask(struct thread_set *ts, int defgrp, char **err)
 	}
 
 	/* update the thread_set */
-	if (!thread_set_first_group(&new_ts)) {
+	if (!thread_set_nth_group(&new_ts, 0)) {
 		memprintf(err, "'thread' directive only references non-existing threads");
 		return -1;
 	}