diff --git a/src/mux_h1.c b/src/mux_h1.c
index 19fce077e..aa224d34f 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -4455,7 +4455,7 @@ static size_t h1_nego_ff(struct stconn *sc, struct buffer *input, size_t count,
 	struct h1s *h1s = __sc_mux_strm(sc);
 	struct h1c *h1c = h1s->h1c;
 	struct h1m *h1m = (!(h1c->flags & H1C_F_IS_BACK) ? &h1s->res : &h1s->req);
-	size_t sz, prefix = 0, suffix = 0, ret = 0;
+	size_t sz, offset = 0, ret = 0;
 
 	TRACE_ENTER(H1_EV_STRM_SEND, h1c->conn, h1s, 0, (size_t[]){count});
 
@@ -4494,17 +4494,15 @@ static size_t h1_nego_ff(struct stconn *sc, struct buffer *input, size_t count,
 			else {
 				/* The producer does not know the chunk size, thus this will be emitted at the
 				 * end, in done_ff(). So splicing cannot be used (see TODO below).
-				 * We will reserve 12 bytes to handle at most 4Go chunk with all CRLFs !
-				 * (<8-bytes SIZE><CRLF><CHUNK-DATA><CRLF>, 10 bytes at the beginning and
-				 *  2 bytes reserved at the end)
+				 * We will reserve 10 bytes to handle at most 4Go chunk !
+				 * (<8-bytes SIZE><CRLF><CHUNK-DATA>)
 				 */
 				if (count > MAX_RANGE(unsigned int))
 					count = MAX_RANGE(unsigned int);
-				prefix = 10;
-				suffix = 2;
+				offset = 10;
 				/* Add 2 more bytes to finish the previous chunk */
 				if (h1m->state == H1_MSG_CHUNK_CRLF)
-					prefix += 2;
+					offset += 2;
 				goto no_splicing;
 			}
 		}
@@ -4540,7 +4538,7 @@ static size_t h1_nego_ff(struct stconn *sc, struct buffer *input, size_t count,
 	if (b_space_wraps(&h1c->obuf))
 		b_slow_realign(&h1c->obuf, trash.area, b_data(&h1c->obuf));
 
-	if (b_contig_space(&h1c->obuf) <= prefix + suffix) {
+	if (b_contig_space(&h1c->obuf) <= offset) {
 		h1c->flags |= H1C_F_OUT_FULL;
 		h1s->sd->iobuf.flags |= IOBUF_FL_FF_BLOCKED;
 		TRACE_STATE("output buffer full", H1_EV_STRM_SEND|H1_EV_H1S_BLK, h1c->conn, h1s);
@@ -4548,12 +4546,12 @@ static size_t h1_nego_ff(struct stconn *sc, struct buffer *input, size_t count,
 	}
 
 	/* Cannot forward more than available room in output buffer */
-	sz = b_contig_space(&h1c->obuf) - prefix - suffix;
+	sz = b_contig_space(&h1c->obuf) - offset;
 	if (count > sz)
 		count = sz;
 
 	h1s->sd->iobuf.buf = &h1c->obuf;
-	h1s->sd->iobuf.offset = prefix;
+	h1s->sd->iobuf.offset = offset;
 	h1s->sd->iobuf.data = 0;
 
 	/* forward remaining input data */
@@ -4607,13 +4605,10 @@ static size_t h1_done_ff(struct stconn *sc)
 						   b_peek_ofs(&h1c->obuf, b_data(&h1c->obuf) - sd->iobuf.data + sd->iobuf.offset),
 						   sd->iobuf.data);
 			h1_prepend_chunk_size(&buf, sd->iobuf.data, sd->iobuf.offset - ((h1m->state == H1_MSG_CHUNK_CRLF) ?  2 : 0));
-			h1_append_chunk_crlf(&buf);
-			b_add(&h1c->obuf, sd->iobuf.offset + 2);
-			if (h1m->state == H1_MSG_CHUNK_CRLF) {
+			if (h1m->state == H1_MSG_CHUNK_CRLF)
 				h1_prepend_chunk_crlf(&buf);
-				b_add(&h1c->obuf, 2);
-			}
-			h1m->state = H1_MSG_CHUNK_SIZE;
+			b_add(&h1c->obuf, sd->iobuf.offset);
+			h1m->state = H1_MSG_CHUNK_CRLF;
 		}
 
 		total = sd->iobuf.data;