diff --git a/include/haproxy/http_htx.h b/include/haproxy/http_htx.h
index a02c65c00..f90b4cc74 100644
--- a/include/haproxy/http_htx.h
+++ b/include/haproxy/http_htx.h
@@ -47,7 +47,7 @@ int http_replace_req_meth(struct htx *htx, const struct ist meth);
 int http_replace_req_uri(struct htx *htx, const struct ist uri);
 int http_replace_req_path(struct htx *htx, const struct ist path, int with_qs);
 int http_replace_req_query(struct htx *htx, const struct ist query);
-int http_replace_res_status(struct htx *htx, const struct ist status);
+int http_replace_res_status(struct htx *htx, const struct ist status, const struct ist reason);
 int http_replace_res_reason(struct htx *htx, const struct ist reason);
 int http_replace_header_value(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist data);
 int http_replace_header(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist name, const struct ist value);
diff --git a/src/http_ana.c b/src/http_ana.c
index 73b6e7618..bce84b9ee 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -2815,9 +2815,7 @@ int http_res_set_status(unsigned int status, struct ist reason, struct stream *s
 		reason = ist2(str, strlen(str));
 	}
 
-	if (!http_replace_res_status(htx, ist2(trash.area, trash.data)))
-		return -1;
-	if (!http_replace_res_reason(htx, reason))
+	if (!http_replace_res_status(htx, ist2(trash.area, trash.data), reason))
 		return -1;
 	return 0;
 }
diff --git a/src/http_htx.c b/src/http_htx.c
index c572697be..de65a4dd0 100644
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -487,11 +487,11 @@ int http_replace_req_query(struct htx *htx, const struct ist query)
 /* Replace the response status in the HTX message <htx> by <status>. It returns
  * 1 on success, otherwise 0.
 */
-int http_replace_res_status(struct htx *htx, const struct ist status)
+int http_replace_res_status(struct htx *htx, const struct ist status, const struct ist reason)
 {
 	struct buffer *temp = get_trash_chunk();
 	struct htx_sl *sl = http_get_stline(htx);
-	struct ist vsn, reason;
+	struct ist vsn, r;
 
 	if (!sl)
 		return 0;
@@ -499,13 +499,15 @@ int http_replace_res_status(struct htx *htx, const struct ist status)
 	/* Start by copying old uri and version */
 	chunk_memcat(temp, HTX_SL_RES_VPTR(sl), HTX_SL_RES_VLEN(sl)); /* vsn */
 	vsn = ist2(temp->area, HTX_SL_RES_VLEN(sl));
-
-	chunk_memcat(temp, HTX_SL_RES_RPTR(sl), HTX_SL_RES_RLEN(sl)); /* reason */
-	reason = ist2(temp->area + vsn.len, HTX_SL_RES_RLEN(sl));
+	r = reason;
+	if (!isttest(r)) {
+		chunk_memcat(temp, HTX_SL_RES_RPTR(sl), HTX_SL_RES_RLEN(sl)); /* reason */
+		r = ist2(temp->area + vsn.len, HTX_SL_RES_RLEN(sl));
+	}
 
 	/* create the new start line */
 	sl->info.res.status = strl2ui(status.ptr, status.len);
-	return http_replace_stline(htx, vsn, status, reason);
+	return http_replace_stline(htx, vsn, status, r);
 }
 
 /* Replace the response reason in the HTX message <htx> by <reason>. It returns