diff --git a/src/os/win32/ngx_win32_config.h b/src/os/win32/ngx_win32_config.h
index f098eae36..cc4c375eb 100644
--- a/src/os/win32/ngx_win32_config.h
+++ b/src/os/win32/ngx_win32_config.h
@@ -9,7 +9,7 @@
 
 
 #define WIN32         0x0400
-#define _WIN32_WINNT  0x0500
+#define _WIN32_WINNT  0x0501
 
 
 #define STRICT