diff --git a/components/codetools/fileprocs.pas b/components/codetools/fileprocs.pas
index 0b8ab3d804..fac73a0f04 100644
--- a/components/codetools/fileprocs.pas
+++ b/components/codetools/fileprocs.pas
@@ -1141,8 +1141,8 @@ begin
     try
       // read the first 1024 bytes
       Len:=1024;
-      SetLength(Buf,1024+1);
-      Len:=fs.Read(Buf[1],length(Buf));
+      SetLength(Buf,Len+1);
+      Len:=fs.Read(Buf[1],Len);
       if Len>0 then begin
         Buf[Len+1]:=#0;
         p:=PChar(Buf);