diff --git a/gennghttpxfun.py b/gennghttpxfun.py
index ca40cabb..f76abcde 100755
--- a/gennghttpxfun.py
+++ b/gennghttpxfun.py
@@ -134,6 +134,7 @@ OPTIONS = [
     "backend-http2-settings-timeout",
     "api-max-request-body",
     "backend-max-backoff",
+    "server-name",
 ]
 
 LOGVARS = [
diff --git a/src/memchunk.h b/src/memchunk.h
index 4cfd3b12..d1753ceb 100644
--- a/src/memchunk.h
+++ b/src/memchunk.h
@@ -178,6 +178,9 @@ template <typename Memchunk> struct Memchunks {
   }
   size_t append(const std::string &s) { return append(s.c_str(), s.size()); }
   size_t append(const StringRef &s) { return append(s.c_str(), s.size()); }
+  size_t append(const ImmutableString &s) {
+    return append(s.c_str(), s.size());
+  }
   size_t remove(void *dest, size_t count) {
     if (!tail || count == 0) {
       return 0;
diff --git a/src/shrpx.cc b/src/shrpx.cc
index cd36a1cf..3c7dd888 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -1317,7 +1317,7 @@ void fill_default_config(Config *config) {
 
   auto &httpconf = config->http;
   httpconf.server_name =
-      StringRef::from_lit("nghttpx nghttp2/" NGHTTP2_VERSION);
+      ImmutableString::from_lit("nghttpx nghttp2/" NGHTTP2_VERSION);
   httpconf.no_host_rewrite = true;
   httpconf.request_header_field_buffer = 64_k;
   httpconf.max_request_header_fields = 100;
@@ -2203,6 +2203,9 @@ HTTP:
               599.  If "*"  is used instead of <CODE>,  it matches all
               HTTP  status  code.  If  error  status  code comes  from
               backend server, the custom error pages are not used.
+  --server-name=<NAME>
+              Change server response header field value to <NAME>.
+              Default: )" << get_config()->http.server_name << R"(
 
 API:
   --api-max-request-body=<SIZE>
@@ -2831,6 +2834,7 @@ int main(int argc, char **argv) {
          &flag, 125},
         {SHRPX_OPT_API_MAX_REQUEST_BODY.c_str(), required_argument, &flag, 126},
         {SHRPX_OPT_BACKEND_MAX_BACKOFF.c_str(), required_argument, &flag, 127},
+        {SHRPX_OPT_SERVER_NAME.c_str(), required_argument, &flag, 128},
         {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
@@ -3428,6 +3432,10 @@ int main(int argc, char **argv) {
         // --backend-max-backoff
         cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_MAX_BACKOFF, StringRef{optarg});
         break;
+      case 128:
+        // --server-name
+        cmdcfgs.emplace_back(SHRPX_OPT_SERVER_NAME, StringRef{optarg});
+        break;
       default:
         break;
       }
diff --git a/src/shrpx_config.cc b/src/shrpx_config.cc
index 2eb208a3..08c9fa8a 100644
--- a/src/shrpx_config.cc
+++ b/src/shrpx_config.cc
@@ -1127,6 +1127,11 @@ int option_lookup_token(const char *name, size_t namelen) {
     break;
   case 11:
     switch (name[10]) {
+    case 'e':
+      if (util::strieq_l("server-nam", name, 10)) {
+        return SHRPX_OPTID_SERVER_NAME;
+      }
+      break;
     case 's':
       if (util::strieq_l("backend-tl", name, 10)) {
         return SHRPX_OPTID_BACKEND_TLS;
@@ -2673,6 +2678,11 @@ int parse_config(Config *config, int optid, const StringRef &opt,
   case SHRPX_OPTID_BACKEND_MAX_BACKOFF:
     return parse_duration(&config->conn.downstream->timeout.max_backoff, opt,
                           optarg);
+  case SHRPX_OPTID_SERVER_NAME:
+    config->http.server_name =
+        ImmutableString{std::begin(optarg), std::end(optarg)};
+
+    return 0;
   case SHRPX_OPTID_CONF:
     LOG(WARN) << "conf: ignored";
 
diff --git a/src/shrpx_config.h b/src/shrpx_config.h
index 5ad6585a..0a1b86bb 100644
--- a/src/shrpx_config.h
+++ b/src/shrpx_config.h
@@ -284,6 +284,7 @@ constexpr auto SHRPX_OPT_API_MAX_REQUEST_BODY =
     StringRef::from_lit("api-max-request-body");
 constexpr auto SHRPX_OPT_BACKEND_MAX_BACKOFF =
     StringRef::from_lit("backend-max-backoff");
+constexpr auto SHRPX_OPT_SERVER_NAME = StringRef::from_lit("server-name");
 
 constexpr size_t SHRPX_OBFUSCATED_NODE_LENGTH = 8;
 
@@ -552,7 +553,7 @@ struct HttpConfig {
   std::vector<ErrorPage> error_pages;
   Headers add_request_headers;
   Headers add_response_headers;
-  StringRef server_name;
+  ImmutableString server_name;
   size_t request_header_field_buffer;
   size_t max_request_header_fields;
   size_t response_header_field_buffer;
@@ -843,6 +844,7 @@ enum {
   SHRPX_OPTID_REQUEST_HEADER_FIELD_BUFFER,
   SHRPX_OPTID_RESPONSE_HEADER_FIELD_BUFFER,
   SHRPX_OPTID_RLIMIT_NOFILE,
+  SHRPX_OPTID_SERVER_NAME,
   SHRPX_OPTID_STREAM_READ_TIMEOUT,
   SHRPX_OPTID_STREAM_WRITE_TIMEOUT,
   SHRPX_OPTID_STRIP_INCOMING_FORWARDED,
diff --git a/src/shrpx_http.cc b/src/shrpx_http.cc
index c2939c7e..e54040bf 100644
--- a/src/shrpx_http.cc
+++ b/src/shrpx_http.cc
@@ -51,7 +51,7 @@ StringRef create_error_html(BlockAllocator &balloc, unsigned int http_status) {
   return concat_string_ref(
       balloc, StringRef::from_lit(R"(<!DOCTYPE html><html lang="en"><title>)"),
       status_string, StringRef::from_lit("</title><body><h1>"), status_string,
-      StringRef::from_lit("</h1><footer>"), server_name,
+      StringRef::from_lit("</h1><footer>"), StringRef{server_name},
       StringRef::from_lit("</footer></body></html>"));
 }
 
diff --git a/src/shrpx_http2_upstream.cc b/src/shrpx_http2_upstream.cc
index 8801deeb..202d46ae 100644
--- a/src/shrpx_http2_upstream.cc
+++ b/src/shrpx_http2_upstream.cc
@@ -1307,8 +1307,8 @@ int Http2Upstream::send_reply(Downstream *downstream, const uint8_t *body,
   }
 
   if (!resp.fs.header(http2::HD_SERVER)) {
-    nva.push_back(
-        http2::make_nv_ls_nocopy("server", get_config()->http.server_name));
+    nva.push_back(http2::make_nv_ls_nocopy(
+        "server", StringRef{get_config()->http.server_name}));
   }
 
   for (auto &p : httpconf.add_response_headers) {
@@ -1359,7 +1359,8 @@ int Http2Upstream::error_reply(Downstream *downstream,
   auto nva = std::array<nghttp2_nv, 5>{
       {http2::make_nv_ls_nocopy(":status", response_status),
        http2::make_nv_ll("content-type", "text/html; charset=UTF-8"),
-       http2::make_nv_ls_nocopy("server", get_config()->http.server_name),
+       http2::make_nv_ls_nocopy("server",
+                                StringRef{get_config()->http.server_name}),
        http2::make_nv_ls_nocopy("content-length", content_length),
        http2::make_nv_ls_nocopy("date", date)}};
 
@@ -1506,7 +1507,8 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream) {
   http2::copy_headers_to_nva_nocopy(nva, resp.fs.headers());
 
   if (!get_config()->http2_proxy) {
-    nva.push_back(http2::make_nv_ls_nocopy("server", httpconf.server_name));
+    nva.push_back(
+        http2::make_nv_ls_nocopy("server", StringRef{httpconf.server_name}));
   } else {
     auto server = resp.fs.header(http2::HD_SERVER);
     if (server) {