NGX_FILE_WRONLY
diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index e05cb44..c4eccf1 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -22,6 +22,7 @@
#define ngx_open_file_n "open()"
#define NGX_FILE_RDONLY O_RDONLY
+#define NGX_FILE_WRONLY O_WRONLY
#define NGX_FILE_RDWR O_RDWR
#define NGX_FILE_CREATE_OR_OPEN O_CREAT
#define NGX_FILE_OPEN 0
diff --git a/src/os/win32/ngx_files.h b/src/os/win32/ngx_files.h
index 7db5c81..f5a97f8 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h
@@ -38,6 +38,7 @@
#define ngx_open_file_n "CreateFile()"
#define NGX_FILE_RDONLY GENERIC_READ
+#define NGX_FILE_WRONLY GENERIC_WRITE
#define NGX_FILE_RDWR GENERIC_READ|GENERIC_WRITE
#define NGX_FILE_CREATE_OR_OPEN OPEN_ALWAYS
#define NGX_FILE_OPEN OPEN_EXISTING
