diff --git a/doc/configuration.txt b/doc/configuration.txt
index 971c26e8f..bb7d56794 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -12218,6 +12218,12 @@ query : string
   using the "found" matching method. This fetch is the completemnt of "path"
   which stops before the question mark.
 
+req.hdr_names([<delim>]) : string
+  This builds a string made from the concatenation of all header names as they
+  appear in the request when the rule is evaluated. The default delimiter is
+  the comma (',') but it may be overridden as an optional argument <delim>. In
+  this case, only the first character of <delim> is considered.
+
 req.ver : string
 req_ver : string (deprecated)
   Returns the version string from the HTTP request, for example "1.1". This can
@@ -12314,6 +12320,12 @@ shdr_ip([<name>[,<occ>]]) : ip (deprecated)
   Negative values indicate positions relative to the last one, with -1 being
   the last one. This can be useful to learn some data into a stick table.
 
+res.hdr_names([<delim>]) : string
+  This builds a string made from the concatenation of all header names as they
+  appear in the response when the rule is evaluated. The default delimiter is
+  the comma (',') but it may be overridden as an optional argument <delim>. In
+  this case, only the first character of <delim> is considered.
+
 res.hdr_val([<name>[,<occ>]]) : integer
 shdr_val([<name>[,<occ>]]) : integer (deprecated)
   This extracts the last occurrence of header <name> in an HTTP response, and
diff --git a/src/proto_http.c b/src/proto_http.c
index 0a6ef9f7d..4484bcf48 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -10232,6 +10232,39 @@ smp_fetch_fhdr_cnt(struct proxy *px, struct session *l4, void *l7, unsigned int
 	return 1;
 }
 
+static int
+smp_fetch_hdr_names(struct proxy *px, struct session *l4, void *l7, unsigned int opt,
+                    const struct arg *args, struct sample *smp, const char *kw)
+{
+	struct http_txn *txn = l7;
+	struct hdr_idx *idx = &txn->hdr_idx;
+	struct hdr_ctx ctx;
+	const struct http_msg *msg = ((opt & SMP_OPT_DIR) == SMP_OPT_DIR_REQ) ? &txn->req : &txn->rsp;
+	struct chunk *temp;
+	char del = ',';
+
+	if (args && args->type == ARGT_STR)
+		del = *args[0].data.str.str;
+
+	CHECK_HTTP_MESSAGE_FIRST();
+
+	temp = get_trash_chunk();
+
+	ctx.idx = 0;
+	while (http_find_next_header(msg->chn->buf->p, idx, &ctx)) {
+		if (temp->len)
+			temp->str[temp->len++] = del;
+		memcpy(temp->str + temp->len, ctx.line, ctx.del);
+		temp->len += ctx.del;
+	}
+
+	smp->type = SMP_T_STR;
+	smp->data.str.str = temp->str;
+	smp->data.str.len = temp->len;
+	smp->flags = SMP_F_VOL_HDR;
+	return 1;
+}
+
 /* Fetch an HTTP header. A pointer to the beginning of the value is returned.
  * Accepts an optional argument of type string containing the header field name,
  * and an optional argument of type signed or unsigned integer to request an
@@ -11884,6 +11917,7 @@ static struct sample_fetch_kw_list sample_fetch_keywords = {ILH, {
 	{ "req.hdr",         smp_fetch_hdr,            ARG2(0,STR,SINT), val_hdr, SMP_T_STR,  SMP_USE_HRQHV },
 	{ "req.hdr_cnt",     smp_fetch_hdr_cnt,        ARG1(0,STR),      NULL,    SMP_T_UINT, SMP_USE_HRQHV },
 	{ "req.hdr_ip",      smp_fetch_hdr_ip,         ARG2(0,STR,SINT), val_hdr, SMP_T_IPV4, SMP_USE_HRQHV },
+	{ "req.hdr_names",   smp_fetch_hdr_names,      ARG1(0,STR),      NULL,    SMP_T_STR,  SMP_USE_HRQHV },
 	{ "req.hdr_val",     smp_fetch_hdr_val,        ARG2(0,STR,SINT), val_hdr, SMP_T_UINT, SMP_USE_HRQHV },
 
 	/* explicit req.{cook,hdr} are used to force the fetch direction to be response-only */
@@ -11896,6 +11930,7 @@ static struct sample_fetch_kw_list sample_fetch_keywords = {ILH, {
 	{ "res.hdr",         smp_fetch_hdr,            ARG2(0,STR,SINT), val_hdr, SMP_T_STR,  SMP_USE_HRSHV },
 	{ "res.hdr_cnt",     smp_fetch_hdr_cnt,        ARG1(0,STR),      NULL,    SMP_T_UINT, SMP_USE_HRSHV },
 	{ "res.hdr_ip",      smp_fetch_hdr_ip,         ARG2(0,STR,SINT), val_hdr, SMP_T_IPV4, SMP_USE_HRSHV },
+	{ "res.hdr_names",   smp_fetch_hdr_names,      ARG1(0,STR),      NULL,    SMP_T_STR,  SMP_USE_HRSHV },
 	{ "res.hdr_val",     smp_fetch_hdr_val,        ARG2(0,STR,SINT), val_hdr, SMP_T_UINT, SMP_USE_HRSHV },
 
 	/* scook is valid only on the response and is used for ACL compatibility */