diff --git a/autotests/export/latex/languages/ru_auto-legacy-luatex.lyx b/autotests/export/latex/languages/ru_auto-legacy-luatex.lyx
new file mode 100644
index 0000000000..e6aa96999a
--- /dev/null
+++ b/autotests/export/latex/languages/ru_auto-legacy-luatex.lyx
@@ -0,0 +1,177 @@
+#LyX 2.4 created this file. For more info see https://www.lyx.org/
+\lyxformat 573
+\begin_document
+\begin_header
+\save_transient_properties true
+\origin unavailable
+\textclass article
+\begin_preamble
+% DO NOT ALTER THIS PREAMBLE!!! 
+%
+%This preamble is designed to ensure that the document prints
+% out as advertised. If you mess with this preamble,
+% parts of the document may not print out as expected. If you
+% have problems LaTeXing this file, please contact 
+% the documentation team
+% email: lyx-docs@lists.lyx.org
+
+% the pages of the TOC is numbered roman
+% and a pdf-bookmark for the TOC is added
+\pagenumbering{roman}
+\let\myTOC\tableofcontents
+\renewcommand\tableofcontents{%
+  \pdfbookmark[1]{\contentsname}{}
+  \myTOC
+  \cleardoublepage
+  \pagenumbering{arabic} }
+\end_preamble
+\use_default_options false
+\maintain_unincluded_children false
+\language russian
+\language_package default
+\inputencoding auto-legacy
+\fontencoding auto
+\font_roman "default" "DejaVu Serif"
+\font_sans "default" "DejaVu Sans"
+\font_typewriter "default" "DejaVu Sans Mono"
+\font_math "auto" "auto"
+\font_default_family default
+\use_non_tex_fonts false
+\font_sc false
+\font_osf false
+\font_sf_scale 100 100
+\font_tt_scale 100 100
+\use_microtype false
+\use_dash_ligatures false
+\graphics default
+\default_output_format pdf5
+\output_sync 0
+\bibtex_command default
+\index_command default
+\float_placement class
+\float_alignment class
+\paperfontsize 12
+\spacing single
+\use_hyperref true
+\pdf_title "Введение в LyX"
+\pdf_author "LyX Team"
+\pdf_subject "LyX-documentation Intro"
+\pdf_keywords "LyX, documentation"
+\pdf_bookmarks true
+\pdf_bookmarksnumbered true
+\pdf_bookmarksopen true
+\pdf_bookmarksopenlevel 2
+\pdf_breaklinks false
+\pdf_pdfborder false
+\pdf_colorlinks true
+\pdf_backref false
+\pdf_pdfusetitle false
+\pdf_quoted_options "linkcolor=black, citecolor=black, urlcolor=blue, filecolor=blue, pdfpagelayout=OneColumn, pdfnewwindow=true, pdfstartview=XYZ, plainpages=false"
+\papersize a4paper
+\use_geometry false
+\use_package amsmath 1
+\use_package amssymb 1
+\use_package cancel 1
+\use_package esint 1
+\use_package mathdots 1
+\use_package mathtools 1
+\use_package mhchem 1
+\use_package stackrel 1
+\use_package stmaryrd 1
+\use_package undertilde 1
+\cite_engine basic
+\cite_engine_type default
+\biblio_style plain
+\use_bibtopic false
+\use_indices false
+\paperorientation portrait
+\suppress_date false
+\justification true
+\use_refstyle 0
+\use_minted 0
+\index Предметный указатель
+\shortcut idx
+\color #008000
+\end_index
+\secnumdepth 3
+\tocdepth 2
+\paragraph_separation indent
+\paragraph_indentation default
+\is_math_indent 0
+\math_numbering_side default
+\quotes_style russian
+\dynamic_quotes 0
+\papercolumns 1
+\papersides 1
+\paperpagestyle default
+\tablestyle default
+\tracking_changes false
+\output_changes false
+\html_math_output 0
+\html_css_as_file 0
+\html_be_strict false
+\end_header
+
+\begin_body
+
+\begin_layout Title
+Введение в \SpecialChar LyX
+
+\end_layout
+
+\begin_layout Author
+автор: команда разработки \SpecialChar LyX
+
+\begin_inset Newline newline
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset CommandInset toc
+LatexCommand tableofcontents
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Философия \SpecialChar LyX
+
+\end_layout
+
+\begin_layout Subsection
+
+\lang spanish
+What is the problem?
+\end_layout
+
+\begin_layout Standard
+
+\lang spanish
+Babel-Russian uses utf8-encoded auto-strings when detecting Xe/LuaTeX.
+ This leads to wrong output with TeX fonts and legacy 8-bit input encodings,
+ e.g.
+ the ToC-title should be 
+\begin_inset Quotes eld
+\end_inset
+
+Содержание
+\begin_inset Quotes erd
+\end_inset
+
+ but is 
+\begin_inset Quotes eld
+\end_inset
+
+ППППЯППППП
+\begin_inset Quotes erd
+\end_inset
+
+ and to compilation errors.
+\end_layout
+
+\end_body
+\end_document
diff --git a/development/autotests/invertedTests b/development/autotests/invertedTests
index 5721012b1a..3d1dc56d17 100644
--- a/development/autotests/invertedTests
+++ b/development/autotests/invertedTests
@@ -225,8 +225,8 @@ export/doc/(|de/|es/|fr/)UserGuide_pdf4_texF
 
 # Babel-Russian uses UTF-8 for auto-strings if it detects Xe/LuaTeX.
 # This fails unless the inputencoding is set to utf-8, too.
-export/doc/ru/(Intro|Tutorial)_.*_texF
-export/examples/ru/.*LyXified.*_texF
+export/export/latex/languages/ru_auto-legacy-luatex.*_texF
+
 
 # Babel-Ukrainian uses UTF-8 if it detects Xe/LuaTeX (for "\date").
 # With 8-bit TeX fonts this results in:
diff --git a/lib/doc/ru/Intro.lyx b/lib/doc/ru/Intro.lyx
index abc09dd8c5..4add8f12df 100644
--- a/lib/doc/ru/Intro.lyx
+++ b/lib/doc/ru/Intro.lyx
@@ -29,7 +29,7 @@
 \maintain_unincluded_children false
 \language russian
 \language_package default
-\inputencoding auto
+\inputencoding utf8
 \fontencoding global
 \font_roman "default" "DejaVu Serif"
 \font_sans "default" "DejaVu Sans"
diff --git a/lib/doc/ru/Tutorial.lyx b/lib/doc/ru/Tutorial.lyx
index 65f499565a..f8860eb81d 100644
--- a/lib/doc/ru/Tutorial.lyx
+++ b/lib/doc/ru/Tutorial.lyx
@@ -12,7 +12,7 @@ logicalmkup
 \maintain_unincluded_children false
 \language russian
 \language_package default
-\inputencoding auto
+\inputencoding utf8
 \fontencoding global
 \font_roman "default" "DejaVu Serif"
 \font_sans "default" "DejaVu Sans"
diff --git a/lib/examples/ru/Example_%28LyXified%29.lyx b/lib/examples/ru/Example_%28LyXified%29.lyx
index d8e9c21f5f..a4f5ebcd89 100644
--- a/lib/examples/ru/Example_%28LyXified%29.lyx
+++ b/lib/examples/ru/Example_%28LyXified%29.lyx
@@ -9,7 +9,7 @@
 \maintain_unincluded_children false
 \language russian
 \language_package default
-\inputencoding auto
+\inputencoding utf8
 \fontencoding global
 \font_roman "default" "DejaVu Serif"
 \font_sans "default" "DejaVu Sans"
diff --git a/lib/examples/ru/Example_%28raw%29.lyx b/lib/examples/ru/Example_%28raw%29.lyx
index 8ee82616ca..22a15744ba 100644
--- a/lib/examples/ru/Example_%28raw%29.lyx
+++ b/lib/examples/ru/Example_%28raw%29.lyx
@@ -9,7 +9,7 @@
 \maintain_unincluded_children false
 \language russian
 \language_package default
-\inputencoding auto
+\inputencoding utf8
 \fontencoding global
 \font_roman "default" "DejaVu Serif"
 \font_sans "default" "DejaVu Sans"