diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
index 75809d9ad..eb6b6af5c 100644
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -487,7 +487,8 @@ ngx_open_listening_sockets(ngx_cycle_t *cycle)
                 continue;
             }
 
-            s = ngx_socket(ls[i].sockaddr->sa_family, ls[i].type, 0);
+            s = ngx_socket(ls[i].sockaddr->sa_family, ls[i].type,
++                           ls[i].protocol);
 
             if (s == (ngx_socket_t) -1) {
                 ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index 84dd80442..80caaf741 100644
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -24,6 +24,7 @@ struct ngx_listening_s {
     ngx_str_t           addr_text;
 
     int                 type;
+    int                 protocol;
 
     int                 backlog;
     int                 rcvbuf;