diff --git a/examples/shrpx.cc b/examples/shrpx.cc
index 92360851..76906774 100644
--- a/examples/shrpx.cc
+++ b/examples/shrpx.cc
@@ -196,7 +196,7 @@ evconnlistener* create_evlistener(ListenHandler *handler, int family)
      ssl_acceptcb,
      handler,
      LEV_OPT_REUSEABLE | LEV_OPT_CLOSE_ON_FREE,
-     512,
+     get_config()->backlog,
      fd);
   evconnlistener_set_error_cb(evlistener, evlistener_errorcb);
   return evlistener;
@@ -333,6 +333,9 @@ void fill_default_config()
   mod_config()->syslog = false;
   mod_config()->syslog_facility = LOG_DAEMON;
   mod_config()->use_syslog = false;
+
+  // Default accept() backlog
+  mod_config()->backlog = 256;
 }
 } // namespace
 
@@ -424,6 +427,9 @@ void print_help(std::ostream& out)
       << "                       Set syslog facility.\n"
       << "                       Default: "
       << str_syslog_facility(get_config()->syslog_facility) << "\n"
+      << "    --backlog=<NUM>    Set listen backlog size.\n"
+      << "                       Default: "
+      << get_config()->backlog << "\n"
       << "    -h, --help         Print this help.\n"
       << std::endl;
 }
@@ -460,6 +466,7 @@ int main(int argc, char **argv)
       {"conf", required_argument, &flag, 12 },
       {"syslog", no_argument, &flag, 13 },
       {"syslog-facility", required_argument, &flag, 14 },
+      {"backlog", required_argument, &flag, 15 },
       {"help", no_argument, 0, 'h' },
       {0, 0, 0, 0 }
     };
@@ -560,6 +567,10 @@ int main(int argc, char **argv)
         // --syslog-facility
         cmdcfgs.push_back(std::make_pair(SHRPX_OPT_SYSLOG_FACILITY, optarg));
         break;
+      case 15:
+        // --backlog
+        cmdcfgs.push_back(std::make_pair(SHRPX_OPT_BACKLOG, optarg));
+        break;
       default:
         break;
       }
diff --git a/examples/shrpx_config.cc b/examples/shrpx_config.cc
index 0c0874ef..ebba2449 100644
--- a/examples/shrpx_config.cc
+++ b/examples/shrpx_config.cc
@@ -66,6 +66,7 @@ const char SHRPX_OPT_PID_FILE[] = "pid-file";
 const char SHRPX_OPT_USER[] = "user";
 const char SHRPX_OPT_SYSLOG[] = "syslog";
 const char SHRPX_OPT_SYSLOG_FACILITY[] = "syslog-facility";
+const char SHRPX_OPT_BACKLOG[] = "backlog";
 
 Config::Config()
   : verbose(false),
@@ -92,7 +93,8 @@ Config::Config()
     conf_path(0),
     syslog(false),
     syslog_facility(0),
-    use_syslog(false)
+    use_syslog(false),
+    backlog(0)
 {}
 
 namespace {
@@ -238,6 +240,8 @@ int parse_config(const char *opt, const char *optarg)
       return -1;
     }
     mod_config()->syslog_facility = facility;
+  } else if(util::strieq(opt, SHRPX_OPT_BACKLOG)) {
+    mod_config()->backlog = strtol(optarg, 0, 10);
   } else if(util::strieq(opt, "conf")) {
     LOG(WARNING) << "conf is ignored";
   } else {
diff --git a/examples/shrpx_config.h b/examples/shrpx_config.h
index e753b3b7..8b4e25fc 100644
--- a/examples/shrpx_config.h
+++ b/examples/shrpx_config.h
@@ -58,6 +58,7 @@ extern const char SHRPX_OPT_PID_FILE[];
 extern const char SHRPX_OPT_USER[];
 extern const char SHRPX_OPT_SYSLOG[];
 extern const char SHRPX_OPT_SYSLOG_FACILITY[];
+extern const char SHRPX_OPT_BACKLOG[];
 
 union sockaddr_union {
   sockaddr sa;
@@ -100,6 +101,7 @@ struct Config {
   int syslog_facility;
   // This member finally decides syslog is used or not
   bool use_syslog;
+  int backlog;
   Config();
 };