diff --git a/include/haproxy/receiver-t.h b/include/haproxy/receiver-t.h
index d1897de51..976cc70c7 100644
--- a/include/haproxy/receiver-t.h
+++ b/include/haproxy/receiver-t.h
@@ -65,7 +65,7 @@ struct shard_info {
 	uint nbgroups;                         /* number of groups in this shard (=#rx); Zero = unused. */
 	uint nbthreads;                        /* number of threads in this shard (>=nbgroups) */
 	struct receiver *ref;                  /* first one, reference for FDs to duplicate */
-	struct receiver *members[MAX_TGROUPS]; /* all members of the shard (one per thread group) */
+	struct receiver **members; /* all members of the shard (one per thread group) */
 };
 
 /* This describes a receiver with all its characteristics (address, options, etc) */
diff --git a/src/listener.c b/src/listener.c
index 69344d356..5e7d556e8 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -879,6 +879,11 @@ struct shard_info *shard_info_attach(struct receiver *rx, struct shard_info *si)
 			return NULL;
 
 		si->ref = rx;
+		si->members = calloc(global.nbtgroups, sizeof(*si->members));
+		if (si->members == NULL) {
+			free(si);
+			return NULL;
+		}
 	}
 
 	rx->shard_info = si;
@@ -921,8 +926,10 @@ void shard_info_detach(struct receiver *rx)
 	si->members[si->nbgroups] = NULL;
 	si->ref = si->members[0];
 
-	if (!si->nbgroups)
+	if (!si->nbgroups) {
+		free(si->members);
 		free(si);
+	}
 }
 
 /* clones listener <src> and returns the new one. All dynamically allocated