--- a/auto/unix
+++ b/auto/unix
@@ -64,6 +64,21 @@ ngx_param=NGX_TIME_T_LEN; ngx_value=$ngx
 # syscalls, libc calls and some features
 
 
+if [ $NGX_IPV6 = YES ]; then
+    ngx_feature="AF_INET6"
+    ngx_feature_name="NGX_HAVE_INET6"
+    ngx_feature_run=no
+    ngx_feature_incs="#include <sys/socket.h>
+                      #include <netinet/in.h>
+                      #include <arpa/inet.h>"
+    ngx_feature_path=
+    ngx_feature_libs=
+    ngx_feature_test="struct sockaddr_in6  sin6;
+                      sin6.sin6_family = AF_INET6;"
+    . auto/feature
+fi
+
+
 ngx_feature="setproctitle()"
 ngx_feature_name="NGX_HAVE_SETPROCTITLE"
 ngx_feature_run=no
@@ -175,8 +190,8 @@ ngx_feature='mmap("/dev/zero", MAP_SHARE
 ngx_feature_name="NGX_HAVE_MAP_DEVZERO"
 ngx_feature_run=yes
 ngx_feature_incs="#include <sys/mman.h>
-#include <sys/stat.h>
-#include <fcntl.h>"
+                  #include <sys/stat.h>
+                  #include <fcntl.h>"
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test='void *p; int  fd;
@@ -190,7 +205,7 @@ ngx_feature="System V shared memory"
 ngx_feature_name="NGX_HAVE_SYSVSHM"
 ngx_feature_run=yes
 ngx_feature_incs="#include <sys/ipc.h>
-#include <sys/shm.h>"
+                  #include <sys/shm.h>"
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="int  id;
@@ -214,7 +229,7 @@ ngx_feature="ioctl(FIONBIO)"
 ngx_feature_name="NGX_HAVE_FIONBIO"
 ngx_feature_run=no
 ngx_feature_incs="#include <sys/ioctl.h>
-$NGX_INCLUDE_SYS_FILIO_H"
+                  $NGX_INCLUDE_SYS_FILIO_H"
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="int i; i = FIONBIO"