Index: src/natools-smaz_generic-tools.adb
==================================================================
--- src/natools-smaz_generic-tools.adb
+++ src/natools-smaz_generic-tools.adb
@@ -288,11 +288,15 @@
          return Result;
       end New_Offsets;
 
       function New_Values return String is
       begin
-         if Index < Dict.Last_Code then
+         if Index = Dictionary_Code'First then
+            return Dict.Values
+              (Dict.Offsets (Dictionary_Code'Succ (Index))
+               .. Dict.Values'Last);
+         elsif Index < Dict.Last_Code then
             return Dict.Values (1 .. Dict.Offsets (Index) - 1)
               & Dict.Values (Dict.Offsets (Dictionary_Code'Succ (Index))
                              .. Dict.Values'Last);
          else
             return Dict.Values (1 .. Dict.Offsets (Index) - 1);