diff --git a/rtl/unix/sysutils.pp b/rtl/unix/sysutils.pp
index 985b6a092d..9077ee40a2 100644
--- a/rtl/unix/sysutils.pp
+++ b/rtl/unix/sysutils.pp
@@ -1432,6 +1432,7 @@ var
   usecs : Word;
 begin
   DoGetLocalDateTime(SystemTime.Year, SystemTime.Month, SystemTime.Day,SystemTime.Hour, SystemTime.Minute, SystemTime.Second, SystemTime.MilliSecond, usecs);
+  SystemTime.DayOfWeek:=DayOfWeek(EncodeDate(SystemTime.Year,SystemTime.Month,SystemTime.Day))-1;
 end ;
 {$endif}