diff --git a/Contrib/System/Source/System.c b/Contrib/System/Source/System.c
index b18c5eea..adcc9be0 100644
--- a/Contrib/System/Source/System.c
+++ b/Contrib/System/Source/System.c
@@ -72,9 +72,13 @@ TCHAR *GetResultStr(SystemProc *proc)
 
 #ifdef SYSTEM_LOG_DEBUG
 
+#ifndef COUNTOF
+#define COUNTOF(a) ( sizeof(a) / (a[0]) )
+#endif
+
 // System log debugging turned on
-#define SYSTEM_LOG_ADD(a)  { register int _len = lstrlen(syslogbuf); lstrcpyn(syslogbuf + _len, a, COUNTOF(syslogbuf) - _len); }
-#define SYSTEM_LOG_POST     { SYSTEM_LOG_ADD(_T("\n")); WriteToLog(syslogbuf); *syslogbuf = 0; }
+#define SYSTEM_LOG_ADD(a)  do{ register int _len = lstrlen(syslogbuf); lstrcpyn(syslogbuf + _len, a, COUNTOF(syslogbuf) - _len); }while(0)
+#define SYSTEM_LOG_POST     do{ SYSTEM_LOG_ADD(_T("\n")); WriteToLog(syslogbuf); *syslogbuf = 0; }while(0)
 
 HANDLE logfile = NULL;
 TCHAR syslogbuf[4096] = _T("");