diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index e484c81da..d9ee6851e 100644
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -66,7 +66,7 @@ struct ngx_listening_s {
     unsigned            addr_ntop:1;
     unsigned            wildcard:1;
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     unsigned            ipv6only:1;
 #endif
 #if (NGX_HAVE_REUSEPORT)
diff --git a/src/core/ngx_module.h b/src/core/ngx_module.h
index e2fbe9cfa..4ddab5604 100644
--- a/src/core/ngx_module.h
+++ b/src/core/ngx_module.h
@@ -71,11 +71,7 @@
 #define NGX_MODULE_SIGNATURE_8   "0"
 #endif
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
 #define NGX_MODULE_SIGNATURE_9   "1"
-#else
-#define NGX_MODULE_SIGNATURE_9   "0"
-#endif
 
 #if (NGX_HAVE_REUSEPORT)
 #define NGX_MODULE_SIGNATURE_10  "1"
diff --git a/src/http/ngx_http.c b/src/http/ngx_http.c
index 7a46b3ecb..ba559f231 100644
--- a/src/http/ngx_http.c
+++ b/src/http/ngx_http.c
@@ -1756,7 +1756,7 @@ ngx_http_add_listening(ngx_conf_t *cf, ngx_http_conf_addr_t *addr)
     ls->deferred_accept = addr->opt.deferred_accept;
 #endif
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     ls->ipv6only = addr->opt.ipv6only;
 #endif
 
diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index e26c3f722..2daea1013 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -3939,7 +3939,7 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     lsopt.fastopen = -1;
 #endif
     lsopt.wildcard = u.wildcard;
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     lsopt.ipv6only = 1;
 #endif
 
diff --git a/src/http/ngx_http_core_module.h b/src/http/ngx_http_core_module.h
index a8013b184..fdd70041d 100644
--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -69,7 +69,7 @@ typedef struct {
     unsigned                   ssl:1;
 #endif
     unsigned                   http2:1;
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     unsigned                   ipv6only:1;
 #endif
 #if (NGX_HAVE_REUSEPORT)
diff --git a/src/mail/ngx_mail.c b/src/mail/ngx_mail.c
index e5a77b05b..9e560bb7c 100644
--- a/src/mail/ngx_mail.c
+++ b/src/mail/ngx_mail.c
@@ -341,7 +341,7 @@ ngx_mail_optimize_servers(ngx_conf_t *cf, ngx_array_t *ports)
             ls->keepcnt = addr[i].opt.tcp_keepcnt;
 #endif
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
             ls->ipv6only = addr[i].opt.ipv6only;
 #endif
 
diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h
index 1068bb368..7c8422894 100644
--- a/src/mail/ngx_mail.h
+++ b/src/mail/ngx_mail.h
@@ -38,7 +38,7 @@ typedef struct {
 #if (NGX_MAIL_SSL)
     unsigned                ssl:1;
 #endif
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     unsigned                ipv6only:1;
 #endif
     unsigned                so_keepalive:2;
diff --git a/src/mail/ngx_mail_core_module.c b/src/mail/ngx_mail_core_module.c
index 48eacfa28..b974d905c 100644
--- a/src/mail/ngx_mail_core_module.c
+++ b/src/mail/ngx_mail_core_module.c
@@ -353,7 +353,7 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     ls->wildcard = u.wildcard;
     ls->ctx = cf->ctx;
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     ls->ipv6only = 1;
 #endif
 
diff --git a/src/stream/ngx_stream.c b/src/stream/ngx_stream.c
index 7312c3e2e..b982c1fee 100644
--- a/src/stream/ngx_stream.c
+++ b/src/stream/ngx_stream.c
@@ -506,7 +506,7 @@ ngx_stream_optimize_servers(ngx_conf_t *cf, ngx_array_t *ports)
             ls->keepcnt = addr[i].opt.tcp_keepcnt;
 #endif
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
             ls->ipv6only = addr[i].opt.ipv6only;
 #endif
 
diff --git a/src/stream/ngx_stream.h b/src/stream/ngx_stream.h
index a2644a73a..7cb8ae31d 100644
--- a/src/stream/ngx_stream.h
+++ b/src/stream/ngx_stream.h
@@ -52,7 +52,7 @@ typedef struct {
 #if (NGX_STREAM_SSL)
     unsigned                       ssl:1;
 #endif
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     unsigned                       ipv6only:1;
 #endif
 #if (NGX_HAVE_REUSEPORT)
diff --git a/src/stream/ngx_stream_core_module.c b/src/stream/ngx_stream_core_module.c
index 23644f3d2..f7870eed5 100644
--- a/src/stream/ngx_stream_core_module.c
+++ b/src/stream/ngx_stream_core_module.c
@@ -624,7 +624,7 @@ ngx_stream_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     ls->wildcard = u.wildcard;
     ls->ctx = cf->ctx;
 
-#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+#if (NGX_HAVE_INET6)
     ls->ipv6only = 1;
 #endif