diff --git a/addons/ot/src/http.c b/addons/ot/src/http.c
index 0d824ddb55..3376a3b009 100644
--- a/addons/ot/src/http.c
+++ b/addons/ot/src/http.c
@@ -220,12 +220,10 @@ int flt_ot_http_header_set(struct channel *chn, const char *prefix, const char *
 	}
 
 	if (!FLT_OT_STR_ISVALID(prefix)) {
-		ist_name.ptr = (char *)name;
-		ist_name.len = strlen(name);
+		ist_name = ist2((char *)name, strlen(name));
 	}
 	else if (!FLT_OT_STR_ISVALID(name)) {
-		ist_name.ptr = (char *)prefix;
-		ist_name.len = strlen(prefix);
+		ist_name = ist2((char *)prefix, strlen(prefix));
 	}
 	else {
 		buffer = flt_ot_trash_alloc(0, err);
@@ -234,8 +232,7 @@ int flt_ot_http_header_set(struct channel *chn, const char *prefix, const char *
 
 		(void)chunk_printf(buffer, "%s-%s", prefix, name);
 
-		ist_name.ptr = buffer->area;
-		ist_name.len = buffer->data;
+		ist_name = ist2(buffer->area, buffer->data);
 	}
 
 	/* Remove all occurrences of the header. */
diff --git a/addons/promex/service-prometheus.c b/addons/promex/service-prometheus.c
index 6a42a47c30..2070b9c1fd 100644
--- a/addons/promex/service-prometheus.c
+++ b/addons/promex/service-prometheus.c
@@ -1006,7 +1006,7 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
 							val = mkf_u32(FO_STATUS, sv->check.status == appctx->ctx.stats.st_code);
 							check_state = get_check_status_info(appctx->ctx.stats.st_code);
 							labels[2].name = ist("state");
-							labels[2].value = ist2(check_state, strlen(check_state));
+							labels[2].value = ist(check_state);
 							if (!promex_dump_metric(appctx, htx, prefix, &promex_st_metrics[appctx->st2],
 										&val, labels, &out, max))
 								goto full;
diff --git a/include/haproxy/htx.h b/include/haproxy/htx.h
index 93b3206a83..0faf296467 100644
--- a/include/haproxy/htx.h
+++ b/include/haproxy/htx.h
@@ -385,8 +385,8 @@ static inline struct ist htx_get_blk_name(const struct htx *htx, const struct ht
 	switch (type) {
 		case HTX_BLK_HDR:
 		case HTX_BLK_TLR:
-			ret.ptr = htx_get_blk_ptr(htx, blk);
-			ret.len = blk->info & 0xff;
+			ret = ist2(htx_get_blk_ptr(htx, blk),
+				   blk->info & 0xff);
 			break;
 
 		default:
@@ -407,15 +407,15 @@ static inline struct ist htx_get_blk_value(const struct htx *htx, const struct h
 	switch (type) {
 		case HTX_BLK_HDR:
 		case HTX_BLK_TLR:
-			ret.ptr = htx_get_blk_ptr(htx, blk) + (blk->info & 0xff);
-			ret.len = (blk->info >> 8) & 0xfffff;
+			ret = ist2(htx_get_blk_ptr(htx, blk) + (blk->info & 0xff),
+				   (blk->info >> 8) & 0xfffff);
 			break;
 
 		case HTX_BLK_REQ_SL:
 		case HTX_BLK_RES_SL:
 		case HTX_BLK_DATA:
-			ret.ptr = htx_get_blk_ptr(htx, blk);
-			ret.len = blk->info & 0xfffffff;
+			ret = ist2(htx_get_blk_ptr(htx, blk),
+				   blk->info & 0xfffffff);
 			break;
 
 		default:
diff --git a/src/hlua.c b/src/hlua.c
index a158c46b4f..4bce23f760 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -6315,8 +6315,7 @@ static int _hlua_http_msg_dup(struct http_msg *msg, lua_State *L, size_t offset,
 
 			case HTX_BLK_DATA:
 				v = htx_get_blk_value(htx, blk);
-				v.ptr += offset;
-				v.len -= offset;
+				v = istadv(v, offset);
 				if (v.len > len)
 					v.len = len;
 
@@ -6417,7 +6416,7 @@ static void _hlua_http_msg_delete(struct http_msg *msg, struct filter *filter, s
 		v.ptr += htxret.ret;
 		if (v.len > len)
 			v.len  = len;
-		blk = htx_replace_blk_value(htx, blk, v, ist2(NULL, 0));
+		blk = htx_replace_blk_value(htx, blk, v, IST_NULL);
 		len -= v.len;
 		ret += v.len;
 	}
diff --git a/src/stream.c b/src/stream.c
index 27062ea4b8..89e85d88de 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -3010,7 +3010,7 @@ static enum act_parse_ret stream_parse_switch_mode(const char **args, int *cur_a
 			return ACT_RET_PRS_ERR;
 		}
 
-		proto = ist2(args[*cur_arg+2], strlen(args[*cur_arg+2]));
+		proto = ist(args[*cur_arg + 2]);
 		mux_proto = get_mux_proto(proto);
 		if (!mux_proto) {
 			memprintf(err, "'%s %s': '%s' expects a valid MUX protocol, if specified (got '%s')",