diff --git a/addons/promex/service-prometheus.c b/addons/promex/service-prometheus.c
index 21660ff76..aeec42aa5 100644
--- a/addons/promex/service-prometheus.c
+++ b/addons/promex/service-prometheus.c
@@ -412,24 +412,21 @@ static int promex_ts_val_to_str(struct buffer *out, struct field *f, size_t max)
 	return 1;
 }
 
-/* Dump the time series header lines for <metric>. It is its #HELP and #TYPE
+/* Dump the time series header lines for the metric <name>. It is its #HELP and #TYPE
  * strings. It returns 1 on success. Otherwise, if <out> length exceeds <max>,
  * it returns 0.
  */
-static int promex_dump_ts_header(struct appctx *appctx, const struct promex_metric *metric,
-				 const struct ist name, const struct ist d,
+static int promex_dump_ts_header(const struct ist name, const struct ist desc, enum promex_mt_type type,
 				 struct ist *out, size_t max)
 {
-	struct promex_ctx *ctx = appctx->svcctx;
-	struct ist type;
-	struct ist desc;
+	struct ist t;
 
-	switch (metric->type) {
+	switch (type) {
 		case PROMEX_MT_COUNTER:
-			type = ist("counter");
+			t = ist("counter");
 			break;
 		default:
-			type = ist("gauge");
+			t = ist("gauge");
 	}
 
 	if (istcat(out, ist("# HELP "), max) == -1 ||
@@ -437,18 +434,16 @@ static int promex_dump_ts_header(struct appctx *appctx, const struct promex_metr
 	    istcat(out, ist(" "), max) == -1)
 		goto full;
 
-	if (isttest(d))
-		desc = d;
-	else if (metric->flags & PROMEX_FL_INFO_METRIC)
-		desc = ist(info_fields[ctx->field_num].desc);
-	else if (!isttest(promex_st_metric_desc[ctx->field_num]))
-		desc = ist(stat_fields[ctx->field_num].desc);
-
-	if (istcat(out, desc, max) == -1 ||
-	    istcat(out, ist("\n# TYPE "), max) == -1 ||
+	if (istcat(out, ist("# HELP "), max) == -1 ||
 	    istcat(out, name, max) == -1 ||
 	    istcat(out, ist(" "), max) == -1 ||
-	    istcat(out, type, max) == -1 ||
+	    istcat(out, desc, max) == -1)
+		goto full;
+
+	if (istcat(out, ist("\n# TYPE "), max) == -1 ||
+	    istcat(out, name, max) == -1 ||
+	    istcat(out, ist(" "), max) == -1 ||
+	    istcat(out, t, max) == -1 ||
 	    istcat(out, ist("\n"), max) == -1)
 		goto full;
 
@@ -458,31 +453,32 @@ static int promex_dump_ts_header(struct appctx *appctx, const struct promex_metr
 	return 0;
 }
 
-/* Dump the time series for <metric>. It starts by the metric name followed by
+/* Dump the time series for the metric <name>. It starts by the metric name followed by
  * its labels (proxy name, server name...) between braces and finally its
  * value. If not already done, the header lines are dumped first. It returns 1
  * on success. Otherwise if <out> length exceeds <max>, it returns 0.
  */
 static int promex_dump_ts(struct appctx *appctx, struct ist prefix,
-			  const struct ist n, const  struct ist desc, const struct promex_metric *metric,
+			  const struct ist name, const  struct ist desc, enum promex_mt_type type,
 			  struct field *val, struct promex_label *labels, struct ist *out, size_t max)
 {
-	struct ist name = { .ptr = (char[PROMEX_MAX_NAME_LEN]){ 0 }, .len = 0 };
+	struct ist n = { .ptr = (char[PROMEX_MAX_NAME_LEN]){ 0 }, .len = 0 };
 	struct promex_ctx *ctx = appctx->svcctx;
 	size_t len = out->len;
 
 	if (out->len + PROMEX_MAX_METRIC_LENGTH > max)
 		return 0;
 
+
 	/* Fill the metric name */
-	istcat(&name, prefix, PROMEX_MAX_NAME_LEN);
-	istcat(&name, (isttest(n) ? n : metric->n), PROMEX_MAX_NAME_LEN);
+	istcat(&n, prefix, PROMEX_MAX_NAME_LEN);
+	istcat(&n, name, PROMEX_MAX_NAME_LEN);
 
 	if ((ctx->flags & PROMEX_FL_METRIC_HDR) &&
-	    !promex_dump_ts_header(appctx, metric, name, desc, out, max))
+	    !promex_dump_ts_header(n, desc, type, out, max))
 		goto full;
 
-	if (istcat(out, name, max) == -1)
+	if (istcat(out, n, max) == -1)
 		goto full;
 
 	if (isttest(labels[0].name)) {
@@ -534,7 +530,7 @@ static int promex_dump_global_metrics(struct appctx *appctx, struct htx *htx)
 	struct promex_ctx *ctx = appctx->svcctx;
 	struct field val;
 	struct channel *chn = sc_ic(appctx_sc(appctx));
-	struct ist out = ist2(trash.area, 0);
+	struct ist name, desc, out = ist2(trash.area, 0);
 	size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
 	int ret = 1;
 
@@ -547,6 +543,9 @@ static int promex_dump_global_metrics(struct appctx *appctx, struct htx *htx)
 		if (!(promex_global_metrics[ctx->field_num].flags & ctx->flags))
 			continue;
 
+		name = promex_global_metrics[ctx->field_num].n;
+		desc = ist(info_fields[ctx->field_num].desc);
+
 		switch (ctx->field_num) {
 			case INF_BUILD_INFO:
 				labels[0].name  = ist("version");
@@ -558,8 +557,8 @@ static int promex_dump_global_metrics(struct appctx *appctx, struct htx *htx)
 				val = info[ctx->field_num];
 		}
 
-		if (!promex_dump_ts(appctx, prefix, IST_NULL, IST_NULL,
-				    &promex_global_metrics[ctx->field_num],
+		if (!promex_dump_ts(appctx, prefix, name, desc,
+				    promex_global_metrics[ctx->field_num].type,
 				    &val, labels, &out, max))
 			goto full;
 
@@ -588,7 +587,7 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
 	struct stats_module *mod = ctx->p[1];
 	struct field val;
 	struct channel *chn = sc_ic(appctx_sc(appctx));
-	struct ist out = ist2(trash.area, 0);
+	struct ist name, desc, out = ist2(trash.area, 0);
 	size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
 	struct field *stats = stat_l[STATS_DOMAIN_PROXY];
 	int ret = 1;
@@ -598,6 +597,14 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
 		if (!(promex_st_metrics[ctx->field_num].flags & ctx->flags))
 			continue;
 
+		name = promex_st_front_metrics_names[ctx->field_num];
+		desc = promex_st_metric_desc[ctx->field_num];
+
+		if (!isttest(name))
+			name = promex_st_metrics[ctx->field_num].n;
+		if (!isttest(desc))
+			desc = ist(stat_fields[ctx->field_num].desc);
+
 		if (!px)
 			px = proxies_list;
 
@@ -622,10 +629,8 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
 						labels[1].value = promex_front_st[ctx->obj_state];
 						val = mkf_u32(FO_STATUS, state == ctx->obj_state);
 
-						if (!promex_dump_ts(appctx, prefix,
-								    promex_st_front_metrics_names[ctx->field_num],
-								    promex_st_metric_desc[ctx->field_num],
-								    &promex_st_metrics[ctx->field_num],
+						if (!promex_dump_ts(appctx, prefix, name, desc,
+								    promex_st_metrics[ctx->field_num].type,
 								    &val, labels, &out, max))
 							goto full;
 					}
@@ -663,10 +668,8 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
 					val = stats[ctx->field_num];
 			}
 
-			if (!promex_dump_ts(appctx, prefix,
-					    promex_st_front_metrics_names[ctx->field_num],
-					    promex_st_metric_desc[ctx->field_num],
-					    &promex_st_metrics[ctx->field_num],
+			if (!promex_dump_ts(appctx, prefix, name, desc,
+					    promex_st_metrics[ctx->field_num].type,
 					    &val, labels, &out, max))
 				goto full;
 		  next_px:
@@ -694,6 +697,9 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
 		}
 
 		for (;ctx->mod_field_num < mod->stats_count; ctx->mod_field_num++) {
+			name = ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name));
+			desc = ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc));
+
 			if (!px)
 				px = proxies_list;
 
@@ -718,10 +724,8 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
 				val = stats[ctx->field_num + ctx->mod_field_num];
 				metric.type = ((val.type == FN_GAUGE) ? PROMEX_MT_GAUGE : PROMEX_MT_COUNTER);
 
-				if (!promex_dump_ts(appctx, prefix,
-						    ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name)),
-						    ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc)),
-						    &metric, &val, labels, &out, max))
+				if (!promex_dump_ts(appctx, prefix, name, desc, metric.type,
+						    &val, labels, &out, max))
 					goto full;
 
 			next_px2:
@@ -764,7 +768,7 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
 	struct stats_module *mod = ctx->p[2];
 	struct field val;
 	struct channel *chn = sc_ic(appctx_sc(appctx));
-	struct ist out = ist2(trash.area, 0);
+	struct ist name, desc, out = ist2(trash.area, 0);
 	size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
 	struct field *stats = stat_l[STATS_DOMAIN_PROXY];
 	int ret = 1;
@@ -774,6 +778,14 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
 		if (!(promex_st_metrics[ctx->field_num].flags & ctx->flags))
 			continue;
 
+		name = promex_st_li_metrics_names[ctx->field_num];
+		desc = promex_st_metric_desc[ctx->field_num];
+
+		if (!isttest(name))
+			name = promex_st_metrics[ctx->field_num].n;
+		if (!isttest(desc))
+			desc = ist(stat_fields[ctx->field_num].desc);
+
 		if (!px)
 			px = proxies_list;
 
@@ -808,10 +820,8 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
 							val = mkf_u32(FO_STATUS, status == ctx->obj_state);
 							labels[2].name = ist("state");
 							labels[2].value = ist(li_status_st[ctx->obj_state]);
-							if (!promex_dump_ts(appctx, prefix,
-									    promex_st_li_metrics_names[ctx->field_num],
-									    promex_st_metric_desc[ctx->field_num],
-									    &promex_st_metrics[ctx->field_num],
+							if (!promex_dump_ts(appctx, prefix, name, desc,
+									    promex_st_metrics[ctx->field_num].type,
 									    &val, labels, &out, max))
 								goto full;
 						}
@@ -821,10 +831,8 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
 						val = stats[ctx->field_num];
 				}
 
-				if (!promex_dump_ts(appctx, prefix,
-						    promex_st_li_metrics_names[ctx->field_num],
-						    promex_st_metric_desc[ctx->field_num],
-						    &promex_st_metrics[ctx->field_num],
+				if (!promex_dump_ts(appctx, prefix, name, desc,
+						    promex_st_metrics[ctx->field_num].type,
 						    &val, labels, &out, max))
 					goto full;
 			}
@@ -855,6 +863,9 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
 		}
 
 		for (;ctx->mod_field_num < mod->stats_count; ctx->mod_field_num++) {
+			name = ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name));
+			desc = ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc));
+
 			if (!px)
 				px = proxies_list;
 
@@ -889,10 +900,8 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
 					val = stats[ctx->field_num + ctx->mod_field_num];
 					metric.type = ((val.type == FN_GAUGE) ? PROMEX_MT_GAUGE : PROMEX_MT_COUNTER);
 
-					if (!promex_dump_ts(appctx, prefix,
-							    ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name)),
-							    ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc)),
-							    &metric, &val, labels, &out, max))
+					if (!promex_dump_ts(appctx, prefix, name, desc, metric.type,
+							    &val, labels, &out, max))
 						goto full;
 				}
 				li = NULL;
@@ -938,7 +947,7 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 	struct server *sv;
 	struct field val;
 	struct channel *chn = sc_ic(appctx_sc(appctx));
-	struct ist out = ist2(trash.area, 0);
+	struct ist name, desc, out = ist2(trash.area, 0);
 	size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
 	struct field *stats = stat_l[STATS_DOMAIN_PROXY];
 	int ret = 1;
@@ -951,6 +960,14 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 		if (!(promex_st_metrics[ctx->field_num].flags & ctx->flags))
 			continue;
 
+		name = promex_st_back_metrics_names[ctx->field_num];
+		desc = promex_st_metric_desc[ctx->field_num];
+
+		if (!isttest(name))
+			name = promex_st_metrics[ctx->field_num].n;
+		if (!isttest(desc))
+			desc = ist(stat_fields[ctx->field_num].desc);
+
 		if (!px)
 			px = proxies_list;
 
@@ -985,10 +1002,8 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 						val = mkf_u32(FN_GAUGE, srv_state_count[ctx->obj_state]);
 						labels[1].name = ist("state");
 						labels[1].value = promex_srv_st[ctx->obj_state];
-						if (!promex_dump_ts(appctx, prefix,
-								    promex_st_back_metrics_names[ctx->field_num],
-								    promex_st_metric_desc[ctx->field_num],
-								    &promex_st_metrics[ctx->field_num],
+						if (!promex_dump_ts(appctx, prefix, name, desc,
+								    promex_st_metrics[ctx->field_num].type,
 								    &val, labels, &out, max))
 							goto full;
 					}
@@ -1012,10 +1027,8 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 						check_state = get_check_status_info(ctx->obj_state);
 						labels[1].name = ist("state");
 						labels[1].value = ist(check_state);
-						if (!promex_dump_ts(appctx, prefix,
-								    promex_st_back_metrics_names[ctx->field_num],
-								    promex_st_metric_desc[ctx->field_num],
-								    &promex_st_metrics[ctx->field_num],
+						if (!promex_dump_ts(appctx, prefix, name, desc,
+								    promex_st_metrics[ctx->field_num].type,
 								    &val, labels, &out, max))
 							goto full;
 					}
@@ -1027,10 +1040,8 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 						labels[1].name = ist("state");
 						labels[1].value = promex_back_st[ctx->obj_state];
 						val = mkf_u32(FO_STATUS, bkd_state == ctx->obj_state);
-						if (!promex_dump_ts(appctx, prefix,
-								    promex_st_back_metrics_names[ctx->field_num],
-								    promex_st_metric_desc[ctx->field_num],
-								    &promex_st_metrics[ctx->field_num],
+						if (!promex_dump_ts(appctx, prefix, name, desc,
+								    promex_st_metrics[ctx->field_num].type,
 								    &val, labels, &out, max))
 							goto full;
 					}
@@ -1098,10 +1109,8 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 					val = stats[ctx->field_num];
 			}
 
-			if (!promex_dump_ts(appctx, prefix,
-					    promex_st_back_metrics_names[ctx->field_num],
-					    promex_st_metric_desc[ctx->field_num],
-					    &promex_st_metrics[ctx->field_num],
+			if (!promex_dump_ts(appctx, prefix, name, desc,
+					    promex_st_metrics[ctx->field_num].type,
 					    &val, labels, &out, max))
 				goto full;
 		  next_px:
@@ -1129,6 +1138,9 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 		}
 
 		for (;ctx->mod_field_num < mod->stats_count; ctx->mod_field_num++) {
+			name = ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name));
+			desc = ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc));
+
 			if (!px)
 				px = proxies_list;
 
@@ -1153,10 +1165,8 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
 				val = stats[ctx->field_num + ctx->mod_field_num];
 				metric.type = ((val.type == FN_GAUGE) ? PROMEX_MT_GAUGE : PROMEX_MT_COUNTER);
 
-				if (!promex_dump_ts(appctx, prefix,
-						    ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name)),
-						    ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc)),
-						    &metric, &val, labels, &out, max))
+				if (!promex_dump_ts(appctx, prefix, name, desc, metric.type,
+						    &val, labels, &out, max))
 					goto full;
 
 			next_px2:
@@ -1198,7 +1208,7 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 	struct stats_module *mod = ctx->p[2];
 	struct field val;
 	struct channel *chn = sc_ic(appctx_sc(appctx));
-	struct ist out = ist2(trash.area, 0);
+	struct ist name, desc, out = ist2(trash.area, 0);
 	size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
 	struct field *stats = stat_l[STATS_DOMAIN_PROXY];
 	int ret = 1;
@@ -1210,6 +1220,14 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 		if (!(promex_st_metrics[ctx->field_num].flags & ctx->flags))
 			continue;
 
+		name = promex_st_srv_metrics_names[ctx->field_num];
+		desc = promex_st_metric_desc[ctx->field_num];
+
+		if (!isttest(name))
+			name = promex_st_metrics[ctx->field_num].n;
+		if (!isttest(desc))
+			desc = ist(stat_fields[ctx->field_num].desc);
+
 		if (!px)
 			px = proxies_list;
 
@@ -1243,10 +1261,8 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 							val = mkf_u32(FO_STATUS, state == ctx->obj_state);
 							labels[2].name = ist("state");
 							labels[2].value = promex_srv_st[ctx->obj_state];
-							if (!promex_dump_ts(appctx, prefix,
-									    promex_st_srv_metrics_names[ctx->field_num],
-									    promex_st_metric_desc[ctx->field_num],
-									    &promex_st_metrics[ctx->field_num],
+							if (!promex_dump_ts(appctx, prefix, name, desc,
+									    promex_st_metrics[ctx->field_num].type,
 									    &val, labels, &out, max))
 								goto full;
 						}
@@ -1295,10 +1311,8 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 							check_state = get_check_status_info(ctx->obj_state);
 							labels[2].name = ist("state");
 							labels[2].value = ist(check_state);
-							if (!promex_dump_ts(appctx, prefix,
-									    promex_st_srv_metrics_names[ctx->field_num],
-									    promex_st_metric_desc[ctx->field_num],
-									    &promex_st_metrics[ctx->field_num],
+							if (!promex_dump_ts(appctx, prefix, name, desc,
+									    promex_st_metrics[ctx->field_num].type,
 									    &val, labels, &out, max))
 								goto full;
 						}
@@ -1343,10 +1357,8 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 						val = stats[ctx->field_num];
 				}
 
-				if (!promex_dump_ts(appctx, prefix,
-						    promex_st_srv_metrics_names[ctx->field_num],
-						    promex_st_metric_desc[ctx->field_num],
-						    &promex_st_metrics[ctx->field_num],
+				if (!promex_dump_ts(appctx, prefix, name, desc,
+						    promex_st_metrics[ctx->field_num].type,
 						    &val, labels, &out, max))
 					goto full;
 			  next_sv:
@@ -1378,6 +1390,9 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 		}
 
 		for (;ctx->mod_field_num < mod->stats_count; ctx->mod_field_num++) {
+			name = ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name));
+			desc = ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc));
+
 			if (!px)
 				px = proxies_list;
 
@@ -1413,10 +1428,8 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 					val = stats[ctx->field_num + ctx->mod_field_num];
 					metric.type = ((val.type == FN_GAUGE) ? PROMEX_MT_GAUGE : PROMEX_MT_COUNTER);
 
-					if (!promex_dump_ts(appctx, prefix,
-							    ist2(mod->stats[ctx->mod_field_num].name, strlen(mod->stats[ctx->mod_field_num].name)),
-							    ist2(mod->stats[ctx->mod_field_num].desc, strlen(mod->stats[ctx->mod_field_num].desc)),
-							    &metric, &val, labels, &out, max))
+					if (!promex_dump_ts(appctx, prefix, name, desc, metric.type,
+							    &val, labels, &out, max))
 						goto full;
 
 				  next_sv2:
@@ -1495,7 +1508,7 @@ static int promex_dump_module_metrics(struct appctx *appctx, struct promex_modul
 			if (ret < 0)
 				goto error;
 
-			if (!promex_dump_ts(appctx, prefix, IST_NULL, desc, &metric,
+			if (!promex_dump_ts(appctx, prefix, metric.n, desc, metric.type,
 					    &val, labels, out, max))
 				goto full;