diff --git a/src/port/win32security.c b/src/port/win32security.c
index 66796e0e286bdc0e03064eea4c890db1f9753f68..d3eba9a20b570cb682ccf61f69caf9a0dabcf783 100644
--- a/src/port/win32security.c
+++ b/src/port/win32security.c
@@ -34,7 +34,7 @@ log_error(const char *fmt,...)
 {
 	va_list		ap;
 
-	va_start(fmt, ap);
+	va_start(ap, fmt);
 #ifndef FRONTEND
 	write_stderr(fmt, ap);
 #else