diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index f3f78e804..668719fe5 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -1770,7 +1770,6 @@ ngx_http_fastcgi_process_header(ngx_http_request_t *r)
 #if (NGX_HTTP_CACHE)
 
         if (f->large_stderr && r->cache) {
-            u_char                     *start;
             ssize_t                     len;
             ngx_http_fastcgi_header_t  *fh;
 
diff --git a/src/http/modules/ngx_http_map_module.c b/src/http/modules/ngx_http_map_module.c
index 3245e0413..2b80d0f10 100644
--- a/src/http/modules/ngx_http_map_module.c
+++ b/src/http/modules/ngx_http_map_module.c
@@ -375,7 +375,7 @@ ngx_http_map_cmp_dns_wildcards(const void *one, const void *two)
 static char *
 ngx_http_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf)
 {
-    ngx_int_t                   rc, index;
+    ngx_int_t                   rv, index;
     ngx_str_t                  *value, name;
     ngx_uint_t                  i, key;
     ngx_http_map_conf_ctx_t    *ctx;
@@ -546,19 +546,19 @@ found:
         value[0].data++;
     }
 
-    rc = ngx_hash_add_key(&ctx->keys, &value[0], var,
+    rv = ngx_hash_add_key(&ctx->keys, &value[0], var,
                           (ctx->hostnames) ? NGX_HASH_WILDCARD_KEY : 0);
 
-    if (rc == NGX_OK) {
+    if (rv == NGX_OK) {
         return NGX_CONF_OK;
     }
 
-    if (rc == NGX_DECLINED) {
+    if (rv == NGX_DECLINED) {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "invalid hostname or wildcard \"%V\"", &value[0]);
     }
 
-    if (rc == NGX_BUSY) {
+    if (rv == NGX_BUSY) {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "conflicting parameter \"%V\"", &value[0]);
     }
diff --git a/src/mail/ngx_mail_core_module.c b/src/mail/ngx_mail_core_module.c
index 271afc473..c2192961e 100644
--- a/src/mail/ngx_mail_core_module.c
+++ b/src/mail/ngx_mail_core_module.c
@@ -434,8 +434,7 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
         if (ngx_strncmp(value[i].data, "ipv6only=o", 10) == 0) {
 #if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
-            struct sockaddr  *sa;
-            u_char            buf[NGX_SOCKADDR_STRLEN];
+            u_char  buf[NGX_SOCKADDR_STRLEN];
 
             sa = &ls->u.sockaddr;
 
diff --git a/src/os/win32/ngx_socket.h b/src/os/win32/ngx_socket.h
index f728da211..a9e26c295 100644
--- a/src/os/win32/ngx_socket.h
+++ b/src/os/win32/ngx_socket.h
@@ -21,9 +21,9 @@ typedef int     socklen_t;
 
 
 #define ngx_socket(af, type, proto)                                          \
-    WSASocket(af, type, proto, NULL, 0, WSA_FLAG_OVERLAPPED)
+    WSASocketW(af, type, proto, NULL, 0, WSA_FLAG_OVERLAPPED)
 
-#define ngx_socket_n        "WSASocket()"
+#define ngx_socket_n        "WSASocketW()"
 
 int ngx_nonblocking(ngx_socket_t s);
 int ngx_blocking(ngx_socket_t s);
diff --git a/src/os/win32/ngx_win32_config.h b/src/os/win32/ngx_win32_config.h
index 36a486fa8..f5b5950bb 100644
--- a/src/os/win32/ngx_win32_config.h
+++ b/src/os/win32/ngx_win32_config.h
@@ -21,6 +21,11 @@
 #define _CRT_SECURE_NO_WARNINGS
 #define _CRT_SECURE_NO_DEPRECATE
 
+/* enable gethostbyname() in msvc2015 */
+#if !(NGX_HAVE_INET6)
+#define _WINSOCK_DEPRECATED_NO_WARNINGS
+#endif
+
 /*
  * we need to include <windows.h> explicitly before <winsock2.h> because
  * the warning 4201 is enabled in <windows.h>
diff --git a/src/stream/ngx_stream_core_module.c b/src/stream/ngx_stream_core_module.c
index b02e5ca5a..4fe68187e 100644
--- a/src/stream/ngx_stream_core_module.c
+++ b/src/stream/ngx_stream_core_module.c
@@ -372,8 +372,7 @@ ngx_stream_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
         if (ngx_strncmp(value[i].data, "ipv6only=o", 10) == 0) {
 #if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
-            struct sockaddr  *sa;
-            u_char            buf[NGX_SOCKADDR_STRLEN];
+            u_char  buf[NGX_SOCKADDR_STRLEN];
 
             sa = &ls->u.sockaddr;
 
diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index 1c7877cfd..ea142e722 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c
@@ -528,18 +528,18 @@ ngx_stream_proxy_init_upstream(ngx_stream_session_t *s)
     c = s->connection;
 
     if (c->log->log_level >= NGX_LOG_INFO) {
-        ngx_str_t  s;
+        ngx_str_t  str;
         u_char     addr[NGX_SOCKADDR_STRLEN];
 
-        s.len = NGX_SOCKADDR_STRLEN;
-        s.data = addr;
+        str.len = NGX_SOCKADDR_STRLEN;
+        str.data = addr;
 
-        if (ngx_connection_local_sockaddr(pc, &s, 1) == NGX_OK) {
+        if (ngx_connection_local_sockaddr(pc, &str, 1) == NGX_OK) {
             handler = c->log->handler;
             c->log->handler = NULL;
 
             ngx_log_error(NGX_LOG_INFO, c->log, 0, "proxy %V connected to %V",
-                          &s, u->peer.name);
+                          &str, u->peer.name);
 
             c->log->handler = handler;
         }