diff --git a/src/os_win32.c b/src/os_win32.c
index 2773953..8e908b6 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -137,6 +137,8 @@
 typedef int PSNSECINFOW;
 typedef int STARTUPINFO;
 typedef int PROCESS_INFORMATION;
+typedef int LPSECURITY_ATTRIBUTES;
+# define __stdcall /* empty */
 #endif
 
 #ifndef FEAT_GUI_W32