diff --git a/source/helpers.pas b/source/helpers.pas
index c9d6e1c1..11114d0c 100644
--- a/source/helpers.pas
+++ b/source/helpers.pas
@@ -489,7 +489,7 @@ var
   o: Integer;
 begin
   o := Ord(c);
-  Result := ((o >= 65) and (o <= 90)) or ((o >= 97) and (o <= 122));
+  Result := ((o >= 65) and (o <= 90)) or ((o >= 97) and (o <= 122)) or (o = 95);
 end;