diff --git a/src/os_win32.h b/src/os_win32.h
index 42cbab5..58b179f 100644
--- a/src/os_win32.h
+++ b/src/os_win32.h
@@ -102,6 +102,9 @@
 #endif
 #ifndef PROTO
 # include <windows.h>
+# ifndef SM_CXPADDEDBORDER
+#  define SM_CXPADDEDBORDER     92
+# endif
 #endif
 
 /*