diff --git a/src/mux_h1.c b/src/mux_h1.c
index 7cc7ba6eb..ee12686bb 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -1270,6 +1270,10 @@ static size_t h1_process_output(struct h1c *h1c, struct buffer *buf, size_t coun
 				n = htx_get_blk_name(chn_htx, blk);
 				v = htx_get_blk_value(chn_htx, blk);
 
+				/* Skip all pseudo-headers */
+				if (*(n.ptr) == ':')
+					goto skip_hdr;
+
 				if (isteqi(n, ist("transfer-encoding")))
 					h1_parse_xfer_enc_header(h1m, v);
 				else if (isteqi(n, ist("content-length"))) {
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 33ba9bbfe..fababa190 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -4525,6 +4525,10 @@ static size_t h2s_frt_make_resp_headers(struct h2s *h2s, struct htx *htx)
 		    isteq(list[hdr].n, ist("transfer-encoding")))
 			continue;
 
+		/* Skip all pseudo-headers */
+		if (*(list[hdr].n.ptr) == ':')
+			continue;
+
 		if (isteq(list[hdr].n, ist("")))
 			break; // end
 
@@ -4793,6 +4797,10 @@ static size_t h2s_bck_make_req_headers(struct h2s *h2s, struct htx *htx)
 		    isteq(list[hdr].n, ist("transfer-encoding")))
 			continue;
 
+		/* Skip all pseudo-headers */
+		if (*(list[hdr].n.ptr) == ':')
+			continue;
+
 		if (isteq(list[hdr].n, ist("")))
 			break; // end
 
@@ -5263,6 +5271,10 @@ static size_t h2s_make_trailers(struct h2s *h2s, struct htx *htx)
 		    isteq(list[idx].n, ist("transfer-encoding")))
 			continue;
 
+		/* Skip all pseudo-headers */
+		if (*(list[idx].n.ptr) == ':')
+			continue;
+
 		if (!hpack_encode_header(&outbuf, list[idx].n, list[idx].v)) {
 			/* output full */
 			if (b_space_wraps(mbuf))