diff --git a/src/http/ngx_http_header_filter_module.c b/src/http/ngx_http_header_filter_module.c
index 507dc93..2cf1205 100644
--- a/src/http/ngx_http_header_filter_module.c
+++ b/src/http/ngx_http_header_filter_module.c
@@ -95,17 +95,17 @@
     ngx_string("414 Request-URI Too Large"),
     ngx_string("415 Unsupported Media Type"),
     ngx_string("416 Requested Range Not Satisfiable"),
+    ngx_null_string,  /* "417 Expectation Failed" */
+    ngx_null_string,  /* "418 unused" */
+    ngx_null_string,  /* "419 unused" */
+    ngx_null_string,  /* "420 unused" */
+    ngx_string("421 Misdirected Request"),
 
-    /* ngx_null_string, */  /* "417 Expectation Failed" */
-    /* ngx_null_string, */  /* "418 unused" */
-    /* ngx_null_string, */  /* "419 unused" */
-    /* ngx_null_string, */  /* "420 unused" */
-    /* ngx_null_string, */  /* "421 unused" */
     /* ngx_null_string, */  /* "422 Unprocessable Entity" */
     /* ngx_null_string, */  /* "423 Locked" */
     /* ngx_null_string, */  /* "424 Failed Dependency" */
 
-#define NGX_HTTP_LAST_4XX  417
+#define NGX_HTTP_LAST_4XX  422
 #define NGX_HTTP_OFF_5XX   (NGX_HTTP_LAST_4XX - 400 + NGX_HTTP_OFF_4XX)
 
     ngx_string("500 Internal Server Error"),
@@ -113,10 +113,10 @@
     ngx_string("502 Bad Gateway"),
     ngx_string("503 Service Temporarily Unavailable"),
     ngx_string("504 Gateway Time-out"),
-
     ngx_null_string,        /* "505 HTTP Version Not Supported" */
     ngx_null_string,        /* "506 Variant Also Negotiates" */
     ngx_string("507 Insufficient Storage"),
+
     /* ngx_null_string, */  /* "508 unused" */
     /* ngx_null_string, */  /* "509 unused" */
     /* ngx_null_string, */  /* "510 Not Extended" */
diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 8665e5b..31e3539 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2069,7 +2069,7 @@
             ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                           "client attempted to request the server name "
                           "different from that one was negotiated");
-            ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
+            ngx_http_finalize_request(r, NGX_HTTP_MISDIRECTED_REQUEST);
             return NGX_ERROR;
         }
     }
diff --git a/src/http/ngx_http_request.h b/src/http/ngx_http_request.h
index fcd50de..499c1ef 100644
--- a/src/http/ngx_http_request.h
+++ b/src/http/ngx_http_request.h
@@ -95,6 +95,7 @@
 #define NGX_HTTP_REQUEST_URI_TOO_LARGE     414
 #define NGX_HTTP_UNSUPPORTED_MEDIA_TYPE    415
 #define NGX_HTTP_RANGE_NOT_SATISFIABLE     416
+#define NGX_HTTP_MISDIRECTED_REQUEST       421
 
 
 /* Our own HTTP codes */
diff --git a/src/http/ngx_http_special_response.c b/src/http/ngx_http_special_response.c
index 2771e58..64e5acd 100644
--- a/src/http/ngx_http_special_response.c
+++ b/src/http/ngx_http_special_response.c
@@ -210,6 +210,14 @@
 ;
 
 
+static char ngx_http_error_421_page[] =
+"<html>" CRLF
+"<head><title>421 Misdirected Request</title></head>" CRLF
+"<body bgcolor=\"white\">" CRLF
+"<center><h1>421 Misdirected Request</h1></center>" CRLF
+;
+
+
 static char ngx_http_error_494_page[] =
 "<html>" CRLF
 "<head><title>400 Request Header Or Cookie Too Large</title></head>"
@@ -334,8 +342,13 @@
     ngx_string(ngx_http_error_414_page),
     ngx_string(ngx_http_error_415_page),
     ngx_string(ngx_http_error_416_page),
+    ngx_null_string,                     /* 417 */
+    ngx_null_string,                     /* 418 */
+    ngx_null_string,                     /* 419 */
+    ngx_null_string,                     /* 420 */
+    ngx_string(ngx_http_error_421_page),
 
-#define NGX_HTTP_LAST_4XX  417
+#define NGX_HTTP_LAST_4XX  422
 #define NGX_HTTP_OFF_5XX   (NGX_HTTP_LAST_4XX - 400 + NGX_HTTP_OFF_4XX)
 
     ngx_string(ngx_http_error_494_page), /* 494, request header too large */