diff --git a/components/codetools/expreval.pas b/components/codetools/expreval.pas
index 2c7b56c957..e8039c9b02 100644
--- a/components/codetools/expreval.pas
+++ b/components/codetools/expreval.pas
@@ -1379,7 +1379,7 @@ var
   begin
     BracketOpen:=AtomStart;
     BracketLvl:=0;
-    while p<=ExprEnd do begin
+    while AtomStart<ExprEnd do begin
       case AtomStart^ of
       '(': inc(BracketLvl);
       ')':