diff --git a/src/buffer.c b/src/buffer.c
index fe756f781..b4b6e1a1e 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -101,7 +101,7 @@ int buffer_replace2(struct buffer *b, char *pos, char *end, const char *str, int
 	if (len)
 		memcpy(pos, str, len);
 
-	b->i += delta;
+	b_add(b, delta);
 	b_realign_if_empty(b);
 
 	return delta;
@@ -141,7 +141,7 @@ int buffer_insert_line2(struct buffer *b, char *pos, const char *str, int len)
 		pos[len + 1] = '\n';
 	}
 
-	b->i += delta;
+	b_add(b, delta);
 	return delta;
 }
 
diff --git a/src/cache.c b/src/cache.c
index f66106d2d..b86d7bdec 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -560,7 +560,7 @@ static void http_cache_io_handler(struct appctx *appctx)
 			si_applet_cant_put(si);
 			goto out;
 		}
-		res->buf->i += len;
+		b_add(res->buf, len);
 		res->total += len;
 		appctx->st0 = HTTP_CACHE_FWD;
 	}
diff --git a/src/channel.c b/src/channel.c
index 024f27444..2a75042b7 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -96,9 +96,9 @@ int co_inject(struct channel *chn, const char *msg, int len)
 	if (len > max)
 		return max;
 
-	memcpy(chn->buf->p, msg, len);
-	chn->buf->o += len;
-	chn->buf->p = c_ptr(chn, len);
+	memcpy(b_tail(chn->buf), msg, len);
+	b_add(chn->buf, len);
+	c_adv(chn, len);
 	chn->total += len;
 	return -1;
 }
@@ -171,7 +171,7 @@ int ci_putblk(struct channel *chn, const char *blk, int len)
 	if (len > max)
 		memcpy(b_orig(chn->buf), blk + max, len - max);
 
-	chn->buf->i += len;
+	b_add(chn->buf, len);
 	chn->total += len;
 	if (chn->to_forward) {
 		unsigned long fwd = len;
diff --git a/src/compression.c b/src/compression.c
index 397fd9426..2abe9043a 100644
--- a/src/compression.c
+++ b/src/compression.c
@@ -229,7 +229,7 @@ static int identity_add_data(struct comp_ctx *comp_ctx, const char *in_data, int
 
 	memcpy(out_data, in_data, in_len);
 
-	out->i += in_len;
+	b_add(out, in_len);
 
 	return in_len;
 }
@@ -308,7 +308,7 @@ static int rfc195x_add_data(struct comp_ctx *comp_ctx, const char *in_data, int
 		}
 		b_reset(tmpbuf);
 		memcpy(b_tail(tmpbuf), comp_ctx->direct_ptr, comp_ctx->direct_len);
-		tmpbuf->i += comp_ctx->direct_len;
+		b_add(tmpbuf, comp_ctx->direct_len);
 		comp_ctx->direct_ptr = NULL;
 		comp_ctx->direct_len = 0;
 		comp_ctx->queued = tmpbuf;
@@ -318,7 +318,7 @@ static int rfc195x_add_data(struct comp_ctx *comp_ctx, const char *in_data, int
 	if (comp_ctx->queued) {
 		/* data already pending */
 		memcpy(b_tail(comp_ctx->queued), in_data, in_len);
-		comp_ctx->queued->i += in_len;
+		b_add(comp_ctx->queued, in_len);
 		return in_len;
 	}
 
@@ -350,10 +350,10 @@ static int rfc195x_flush_or_finish(struct comp_ctx *comp_ctx, struct buffer *out
 	out_len = out->i;
 
 	if (in_ptr)
-		out->i += slz_encode(strm, b_tail(out), in_ptr, in_len, !finish);
+		b_add(out, slz_encode(strm, b_tail(out), in_ptr, in_len, !finish));
 
 	if (finish)
-		out->i += slz_finish(strm, b_tail(out));
+		b_add(out, slz_finish(strm, b_tail(out)));
 
 	out_len = out->i - out_len;
 
@@ -589,7 +589,7 @@ static int deflate_add_data(struct comp_ctx *comp_ctx, const char *in_data, int
 		return -1;
 
 	/* deflate update the available data out */
-	out->i += out_len - strm->avail_out;
+	b_add(out, out_len - strm->avail_out);
 
 	return in_len - strm->avail_in;
 }
@@ -610,7 +610,7 @@ static int deflate_flush_or_finish(struct comp_ctx *comp_ctx, struct buffer *out
 		return -1;
 
 	out_len = b_room(out) - strm->avail_out;
-	out->i += out_len;
+	b_add(out, out_len);
 
 	/* compression limit */
 	if ((global.comp_rate_lim > 0 && (read_freq_ctr(&global.comp_bps_out) > global.comp_rate_lim)) ||    /* rate */
diff --git a/src/flt_http_comp.c b/src/flt_http_comp.c
index 93653641f..85abb8466 100644
--- a/src/flt_http_comp.c
+++ b/src/flt_http_comp.c
@@ -212,7 +212,7 @@ comp_http_data(struct stream *s, struct filter *filter, struct http_msg *msg)
 			memcpy(b_tail(tmpbuf)+block, buf->data, len-block);
 		c_rew(chn, *nxt);
 
-		tmpbuf->i += len;
+		b_add(tmpbuf, len);
 		ret        = len;
 	}
 	else {
@@ -770,10 +770,10 @@ http_compression_buffer_end(struct comp_state *st, struct stream *s,
 	if (ib->i > 0) {
 		left = ci_contig_data(chn);
 		memcpy(ob->p + ob->i, ci_head(chn), left);
-		ob->i += left;
+		b_add(ob, left);
 		if (ib->i - left) {
 			memcpy(ob->p + ob->i, ib->data, ib->i - left);
-			ob->i += ib->i - left;
+			b_add(ob, ib->i - left);
 		}
 	}
 
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 81772dbbc..934c949b9 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -2742,7 +2742,7 @@ static int h2_frt_decode_headers(struct h2s *h2s, struct buffer *buf, int count,
 	/* now consume the input data */
 	b_del(h2c->dbuf, h2c->dfl);
 	h2c->st0 = H2_CS_FRAME_H;
-	buf->i += outlen;
+	b_add(buf, outlen);
 
 	/* don't send it before returning data!
 	 * FIXME: should we instead try to send it much later, after the
@@ -3091,7 +3091,7 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, const struct buffer *bu
 
 	/* commit the H2 response */
 	h2c->mbuf->p = b_peek(h2c->mbuf, h2c->mbuf->o + outbuf.len);
-	h2c->mbuf->o += outbuf.len;
+	bo_add(h2c->mbuf, outbuf.len);
 	h2s->flags |= H2_SF_HEADERS_SENT;
 
 	/* for now we don't implemented CONTINUATION, so we wait for a
@@ -3337,7 +3337,7 @@ static size_t h2s_frt_make_resp_data(struct h2s *h2s, const struct buffer *buf,
 
 	/* commit the H2 response */
 	h2c->mbuf->p = b_peek(h2c->mbuf, h2c->mbuf->o + size + 9);
-	h2c->mbuf->o += size + 9;
+	bo_add(h2c->mbuf, size + 9);
 
 	/* consume incoming H1 response */
 	if (size > 0) {
diff --git a/src/raw_sock.c b/src/raw_sock.c
index e0bfd1d99..375c453c5 100644
--- a/src/raw_sock.c
+++ b/src/raw_sock.c
@@ -294,7 +294,7 @@ static size_t raw_sock_to_buf(struct connection *conn, struct buffer *buf, size_
 		ret = recv(conn->handle.fd, b_tail(buf), try, 0);
 
 		if (ret > 0) {
-			buf->i += ret;
+			b_add(buf, ret);
 			done += ret;
 			if (ret < try) {
 				/* unfortunately, on level-triggered events, POLL_HUP
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index b47302717..9e3341a31 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -5374,7 +5374,7 @@ static size_t ssl_sock_to_buf(struct connection *conn, struct buffer *buf, size_
 			done++;
 			try--;
 			count--;
-			buf->i++;
+			b_add(buf, 1);
 			conn->tmp_early_data = -1;
 			continue;
 		}
@@ -5421,7 +5421,7 @@ static size_t ssl_sock_to_buf(struct connection *conn, struct buffer *buf, size_
 			goto out_error;
 		}
 		if (ret > 0) {
-			buf->i += ret;
+			b_add(buf, ret);
 			done += ret;
 			count -= ret;
 		}