1 files changed, 1 insertions, 1 deletions
diff --git a/flags.adb b/flags.adb
index 0c0e2b2fc..d1efda36c 100644
--- a/flags.adb
+++ b/flags.adb
@@ -53,7 +53,7 @@ package body Flags is
    end Option_Warning;
 
    function Parse_Option (Opt: String) return Boolean is
-      Beg: Integer := Opt'First;
+      Beg: constant Integer := Opt'First;
    begin
       if Opt'Length > 5 and then Opt (Beg .. Beg + 5) = "--std=" then
          if Opt'Length = 8 then