diff --git a/doc/configuration.txt b/doc/configuration.txt
index 2a5f7dc..132873d 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -4122,7 +4122,7 @@
                 set-header <name> <fmt> | del-header <name> |
                 replace-header <name> <regex-match> <replace-fmt> |
                 replace-value <name> <regex-match> <replace-fmt> |
-                set-status <status> |
+                set-status <status> [reason <str>] |
                 set-log-level <level> | set-mark <mark> | set-tos <tos> |
                 add-acl(<file name>) <key fmt> |
                 del-acl(<file name>) <key fmt> |
@@ -4215,13 +4215,16 @@
         Cache-Control: max-age=3600, private
 
     - "set-status" replaces the response status code with <status> which must
-      be an integer between 100 and 999. Note that the reason is automatically
-      adapted to the new code.
+      be an integer between 100 and 999. Optionally, a custom reason text can be
+      provided defined by <str>, or the default reason for the specified code
+      will be used as a fallback.
 
       Example:
 
         # return "431 Request Header Fields Too Large"
         http-response set-status 431
+        # return "503 Slow Down", custom reason
+        http-response set-status 503 reason "Slow Down".
 
     - "set-nice" sets the "nice" factor of the current request being processed.
       It only has effect against the other requests being processed at the same
diff --git a/doc/lua-api/index.rst b/doc/lua-api/index.rst
index f930277..e04c5b5 100644
--- a/doc/lua-api/index.rst
+++ b/doc/lua-api/index.rst
@@ -1443,13 +1443,15 @@
   :param class_http http: The related http object.
   :param string uri: The new uri.
 
-.. js:function:: HTTP.res_set_status(http, status)
+.. js:function:: HTTP.res_set_status(http, status [, reason])
 
-  Rewrites the response status code with the parameter "code". Note that the
-  reason is automatically adapted to the new code.
+  Rewrites the response status code with the parameter "code".
+
+  If no custom reason is provided, it will be generated from the status.
 
   :param class_http http: The related http object.
   :param integer status: The new response status code.
+  :param string reason: The new response reason (optional).
 
 .. _txn_class:
 
@@ -2080,13 +2082,14 @@
   AppletHTTP.headers["accept"][2] = "*/*, q=0.1"
 ..
 
-.. js:function:: AppletHTTP.set_status(applet, code)
+.. js:function:: AppletHTTP.set_status(applet, code [, reason])
 
   This function sets the HTTP status code for the response. The allowed code are
   from 100 to 599.
 
   :param class_AppletHTTP applet: An :ref:`applethttp_class`
   :param integer code: the status code returned to the client.
+  :param string reason: the status reason returned to the client (optional).
 
 .. js:function:: AppletHTTP.add_header(applet, name, value)
 
diff --git a/include/proto/proto_http.h b/include/proto/proto_http.h
index 5ee2e2f..6c81766 100644
--- a/include/proto/proto_http.h
+++ b/include/proto/proto_http.h
@@ -108,7 +108,7 @@
 int http_remove_header2(struct http_msg *msg, struct hdr_idx *idx, struct hdr_ctx *ctx);
 int http_header_add_tail2(struct http_msg *msg, struct hdr_idx *hdr_idx, const char *text, int len);
 int http_replace_req_line(int action, const char *replace, int len, struct proxy *px, struct stream *s);
-void http_set_status(unsigned int status, struct stream *s);
+void http_set_status(unsigned int status, const char *reason, struct stream *s);
 int http_transform_header_str(struct stream* s, struct http_msg *msg, const char* name,
                               unsigned int name_len, const char *str, struct my_regex *re,
                               int action);
diff --git a/include/types/action.h b/include/types/action.h
index 5a70db0..1c17154 100644
--- a/include/types/action.h
+++ b/include/types/action.h
@@ -135,6 +135,7 @@
 		} cap;
 		struct {
 			unsigned int code;     /* HTTP status code */
+			const char *reason;    /* HTTP status reason */
 		} status;
 		struct {
 			struct sample_expr *expr;
diff --git a/include/types/applet.h b/include/types/applet.h
index 759b905..642c793 100644
--- a/include/types/applet.h
+++ b/include/types/applet.h
@@ -80,6 +80,7 @@
 			int left_bytes;         /* The max amount of bytes that we can read. */
 			int flags;
 			int status;
+			const char *reason;
 			struct task *task;
 		} hlua_apphttp;                 /* used by the Lua HTTP services */
 		struct {
diff --git a/src/hlua.c b/src/hlua.c
index c343a7b..48fcf1a 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -3591,6 +3591,7 @@
 	lua_rawseti(L, -2, 0);
 	appctx->appctx = ctx;
 	appctx->appctx->ctx.hlua_apphttp.status = 200; /* Default status code returned. */
+	appctx->appctx->ctx.hlua_apphttp.reason = NULL; /* Use default reason based on status */
 	appctx->htxn.s = s;
 	appctx->htxn.p = px;
 
@@ -4119,6 +4120,7 @@
 {
 	struct hlua_appctx *appctx = MAY_LJMP(hlua_checkapplet_http(L, 1));
 	int status = MAY_LJMP(luaL_checkinteger(L, 2));
+	const char *reason = MAY_LJMP(luaL_optlstring(L, 3, NULL, NULL));
 
 	if (status < 100 || status > 599) {
 		lua_pushboolean(L, 0);
@@ -4126,6 +4128,7 @@
 	}
 
 	appctx->appctx->ctx.hlua_apphttp.status = status;
+	appctx->appctx->ctx.hlua_apphttp.reason = reason;
 	lua_pushboolean(L, 1);
 	return 1;
 }
@@ -4178,12 +4181,16 @@
 	int hdr_connection = 0;
 	int hdr_contentlength = -1;
 	int hdr_chunked = 0;
+	const char *reason = appctx->appctx->ctx.hlua_apphttp.reason;
+
+	if (reason == NULL)
+		reason = get_reason(appctx->appctx->ctx.hlua_apphttp.status);
 
 	/* Use the same http version than the request. */
 	chunk_appendf(tmp, "HTTP/1.%c %d %s\r\n",
 	              appctx->appctx->ctx.hlua_apphttp.flags & APPLET_HTTP11 ? '1' : '0',
 	              appctx->appctx->ctx.hlua_apphttp.status,
-	              get_reason(appctx->appctx->ctx.hlua_apphttp.status));
+	              reason);
 
 	/* Get the array associated to the field "response" in the object AppletHTTP. */
 	lua_pushvalue(L, 0);
@@ -4737,17 +4744,18 @@
 	return 1;
 }
 
-/* This function set the response code. */
+/* This function set the response code & optionally reason. */
 static int hlua_http_res_set_status(lua_State *L)
 {
 	struct hlua_txn *htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 	unsigned int code = MAY_LJMP(luaL_checkinteger(L, 2));
+	const char *reason = MAY_LJMP(luaL_optlstring(L, 3, NULL, NULL));
 
 	/* Check if a valid response is parsed */
 	if (unlikely(htxn->s->txn->rsp.msg_state < HTTP_MSG_BODY))
 		return 0;
 
-	http_set_status(code, htxn->s);
+	http_set_status(code, reason, htxn->s);
 	return 0;
 }
 
diff --git a/src/proto_http.c b/src/proto_http.c
index 1507001..f7f7545 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -12454,14 +12454,14 @@
 /* This function replace the HTTP status code and the associated message. The
  * variable <status> contains the new status code. This function never fails.
  */
-void http_set_status(unsigned int status, struct stream *s)
+void http_set_status(unsigned int status, const char *reason, struct stream *s)
 {
 	struct http_txn *txn = s->txn;
 	char *cur_ptr, *cur_end;
 	int delta;
 	char *res;
 	int c_l;
-	const char *msg;
+	const char *msg = reason;
 	int msg_len;
 
 	chunk_reset(&trash);
@@ -12472,9 +12472,10 @@
 	trash.str[c_l] = ' ';
 	trash.len = c_l + 1;
 
-	msg = get_reason(status);
+	/* Do we have a custom reason format string? */
+	if (msg == NULL)
+		msg = get_reason(status);
 	msg_len = strlen(msg);
-
 	strncpy(&trash.str[trash.len], msg, trash.size - trash.len);
 	trash.len += msg_len;
 
@@ -12520,7 +12521,7 @@
 enum act_return action_http_set_status(struct act_rule *rule, struct proxy *px,
                                        struct session *sess, struct stream *s, int flags)
 {
-	http_set_status(rule->arg.status.code, s);
+	http_set_status(rule->arg.status.code, rule->arg.status.reason, s);
 	return ACT_RET_CONT;
 }
 
@@ -12596,7 +12597,7 @@
 
 	/* Check if an argument is available */
 	if (!*args[*orig_arg]) {
-		memprintf(err, "expects exactly 1 argument <status>");
+		memprintf(err, "expects 1 argument: <status>; or 3 arguments: <status> reason <fmt>");
 		return ACT_RET_PRS_ERR;
 	}
 
@@ -12608,6 +12609,16 @@
 	}
 
 	(*orig_arg)++;
+
+	/* set custom reason string */
+	rule->arg.status.reason = NULL; // If null, we use the default reason for the status code.
+	if (*args[*orig_arg] && strcmp(args[*orig_arg], "reason") == 0 &&
+	    (*args[*orig_arg + 1] && strcmp(args[*orig_arg + 1], "if") != 0 && strcmp(args[*orig_arg + 1], "unless") != 0)) {
+		(*orig_arg)++;
+		rule->arg.status.reason = strdup(args[*orig_arg]);
+		(*orig_arg)++;
+	}
+
 	return ACT_RET_PRS_OK;
 }