diff --git a/rtl/objpas/classes/streams.inc b/rtl/objpas/classes/streams.inc
index 0f96ed54ad..5e5ac06769 100644
--- a/rtl/objpas/classes/streams.inc
+++ b/rtl/objpas/classes/streams.inc
@@ -1643,7 +1643,7 @@ Var
 begin
   B:=FEncoding.GetBytes(AString);
   if Length(B)>0 then
-    WriteBuffer(B[0],Length(Bytes));
+    WriteBuffer(B[0],Length(B));
 end;
 
 function TStringStream.ReadAnsiString(Count: Longint): AnsiString;