diff --git a/loader/win32.c b/loader/win32.c
index 30960eec99..1195361e43 100644
--- a/loader/win32.c
+++ b/loader/win32.c
@@ -47,7 +47,20 @@
 #include <kstat.h>
 #endif
 
+#if HAVE_VSSCANF
 int vsscanf( const char *str, const char *format, va_list ap);
+#else
+/* system has no vsscanf.  try to provide one */
+static int vsscanf( const char *str, const char *format, va_list ap)
+{
+	long p1 = va_arg(ap, long);
+	long p2 = va_arg(ap, long);
+	long p3 = va_arg(ap, long);
+	long p4 = va_arg(ap, long);
+	long p5 = va_arg(ap, long);
+	return sscanf(str, format, p1, p2, p3, p4, p5);
+}
+#endif
 
 char* def_path = WIN32_PATH;