diff --git a/src/h1_htx.c b/src/h1_htx.c
index ec240a303..b4c49c781 100644
--- a/src/h1_htx.c
+++ b/src/h1_htx.c
@@ -319,7 +319,7 @@ size_t h1_parse_msg_hdrs(struct h1m *h1m, union h1_sl *h1sl, struct htx *dsthtx,
 
 	/* Realing input buffer if necessary */
 	if (b_head(srcbuf) + b_data(srcbuf) > b_wrap(srcbuf))
-		b_slow_realign(srcbuf, trash.area, 0);
+		b_slow_realign_ofs(srcbuf, trash.area, 0);
 
 	if (!h1sl) {
 		/* If there no start-line, be sure to only parse the headers */
@@ -857,7 +857,7 @@ size_t h1_parse_msg_tlrs(struct h1m *h1m, struct htx *dsthtx,
 
 	/* Realing input buffer if necessary */
 	if (b_peek(srcbuf, ofs) > b_tail(srcbuf))
-		b_slow_realign(srcbuf, trash.area, 0);
+		b_slow_realign_ofs(srcbuf, trash.area, 0);
 
 	tlr_h1m.flags = (H1_MF_NO_PHDR|H1_MF_HDRS_ONLY);
 	ret = h1_headers_to_hdr_list(b_peek(srcbuf, ofs), b_tail(srcbuf),
diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index bc9d0232c..6fd76535f 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -1623,7 +1623,7 @@ static int fcgi_conn_handle_values_result(struct fcgi_conn *fconn)
 		 * at this stage because it should be the first record received
 		 * from the FCGI application.
 		 */
-		b_slow_realign(dbuf, trash.area, 0);
+		b_slow_realign_ofs(dbuf, trash.area, 0);
 	}
 
 	inbuf = b_make(b_head(dbuf), b_data(dbuf), 0, fconn->drl);
@@ -2488,7 +2488,7 @@ static int fcgi_strm_handle_end_request(struct fcgi_conn *fconn, struct fcgi_str
 		 * at this stage because it should be the first record received
 		 * from the FCGI application.
 		 */
-		b_slow_realign(dbuf, trash.area, 0);
+		b_slow_realign_ofs(dbuf, trash.area, 0);
 	}
 
 	inbuf = b_make(b_head(dbuf), b_data(dbuf), 0, fconn->drl);
diff --git a/src/mux_h1.c b/src/mux_h1.c
index b90e11c9e..31f64c3f8 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -2519,7 +2519,7 @@ static int h1_recv(struct h1c *h1c)
 	 * it's probably cheaper than doing 2 recv() calls.
 	 */
 	if (b_data(&h1c->ibuf) > 0 && b_data(&h1c->ibuf) < 128)
-		b_slow_realign(&h1c->ibuf, trash.area, 0);
+		b_slow_realign_ofs(&h1c->ibuf, trash.area, sizeof(struct htx));
 
 	/* avoid useless reads after first responses */
 	if (!h1c->h1s ||