Index: src/natools-s_expressions-printers-pretty.adb
==================================================================
--- src/natools-s_expressions-printers-pretty.adb
+++ src/natools-s_expressions-printers-pretty.adb
@@ -286,11 +286,11 @@
                Writer.Write_Raw
                  ((1 .. Count (Output.Cursor) - 1 => Encodings.Space));
             when Tabs =>
                Output.Cursor := Output.Param.Indentation * Output.Indent_Level;
                Writer.Write_Raw ((1 .. Count (Output.Cursor) => Encodings.HT));
-               Output.Cursor := Output.Cursor * Output.Param.Tab_Stop;
+               Output.Cursor := Output.Cursor * Output.Param.Tab_Stop + 1;
             when Tabs_And_Spaces =>
                Output.Cursor := Output.Param.Indentation * Output.Indent_Level
                                 + 1;
                declare
                   Tab_Count : constant Count