diff --git a/flake.nix b/flake.nix
index 27cde7a..fd2aa8c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -52,7 +52,7 @@
             mkdir "$out"
 
             # initial latex compile.
-            pdflatex -synctex=1 -file-line-error \
+            lualatex -synctex=1 -file-line-error \
               -interaction=nonstopmode -output-directory=$out thesis.tex
 
             # handle bibliography.
@@ -64,7 +64,7 @@
               -pvc \
               -outdir="$out" \
               -pdf \
-              -pdflatex="pdflatex -synctex=1 -file-line-error -interaction=nonstopmode" \
+              -pdflatex="lualatex -synctex=1 -file-line-error -interaction=nonstopmode" \
               -use-make thesis.tex
             rm -r "$out"
           '';
@@ -149,7 +149,7 @@
           out=".latexmkout"
           mkdir "$out"
 
-          pdflatex -synctex=1 -file-line-error \
+          lualatex -synctex=1 -file-line-error \
             -interaction=nonstopmode -output-directory=$out thesis.tex
 
           # handle bibliography.
@@ -160,7 +160,7 @@
             -pvc \
             -outdir="$out" \
             -pdf \
-            -pdflatex="pdflatex -synctex=1 -file-line-error -interaction=nonstopmode" \
+            -pdflatex="lualatex -synctex=1 -file-line-error -interaction=nonstopmode" \
             -use-make thesis.tex
 
           # clean up
diff --git a/tex/UTB.tex b/tex/UTB.tex
index 741aa43..87cedff 100644
--- a/tex/UTB.tex
+++ b/tex/UTB.tex
@@ -42,10 +42,13 @@
 % TODO(me):
 % have this disabled when building draft documents with Nix - issue with
 % everyshi version bundled in TexLive `ms` package that Nix bundles.
-% \usepackage{hyperxmp}	% Pro aplikaci standardu PDF/A
+\usepackage{hyperxmp}[2020/03/01]	% Pro aplikaci standardu PDF/A
 \usepackage{pdfpages}	% include raw PDF files directly
 \usepackage{makecell}	% multiline table cells
+\usepackage{colorprofiles}
+% \usepackage[a-2b,mathxmp]{pdfx}[2018/12/22]
 
+% for pdflatex only
 %\pdfminorversion=4
 %\pdfobjcompresslevel=0
 
@@ -137,7 +140,8 @@
 }
 \expandafter\convertDate\pdfcreationdate
 
-\pdfminorversion 4
+% for pdflatex only
+% \pdfminorversion 4
 
 \immediate\pdfobj stream attr{/N 3} file{graphics/sRGBIEC1966-2.1.icm}
 \pdfcatalog{%
@@ -176,8 +180,8 @@
 			pdfkeywords={\klicovaslovacz},
 			%pdfproducer={pdfTeX-1.40.20},
 			pdflang=la,
-			% pdfapart=3,
-			% pdfaconformance=B,
+			pdfapart=3,
+			pdfaconformance=B,
 			pdflang={cz}
 			% use breaklinks to make have long bibtex urls broken
 			% otherwise they go over the margin (known issue)
@@ -194,20 +198,28 @@
 			pdfkeywords={\klicovaslovaen},
 			%pdfproducer={pdfTeX-1.40.20},
 			pdflang=la,
-			% pdfapart=3,
-			% pdfaconformance=B,
-			pdflang={en},
+			pdfapart=3,
+			pdfaconformance=B,
+			pdflang={en-GB},
 			% use breaklinks to make have long bibtex urls broken
 			% otherwise they go over the margin (known issue)
 			breaklinks=true
 		}
 	\fi \fi
-	
-  % TODO(me):
-  % include in the final (non-draft version of the document)
-	% \makeatletter
-	% \includexmp{tex/pdfa-1b}
-	% \makeatother
+
+  % https://tex.stackexchange.com/questions/42641/can-pdflatex-produce-pdf-a?noredirect=1&lq=1
+  % https://webpages.tuni.fi/latex/pdfa-guide.pdf
+  % \begin{filecontents*}[overwrite]{\jobname.xmpdata}
+    % \Title{\nazeven}
+    % \Author{\autor}
+    % \Language{en-GB}
+    % \Subject{\abstrakten}
+    % \Keywords{\klicovaslovaen}
+  % \end{filecontents*}
+  %
+  % \makeatletter
+  % \includexmp{tex/pdfa-1b}
+  % \makeatother
 }
 
 
@@ -802,7 +814,7 @@
 		%\addto\captionsczech{\renewcommand{\tablename}{Tab.}}
 		\renewcommand{\cftfigpresnum}{Obr. }
 	\else \ifenglish
-		\usepackage[english]{babel}	
+		\usepackage[UKenglish]{babel}
 		% Vlastni definice nazvu
 		\addto\captionsenglish{\renewcommand{\contentsname}{\MakeTextUppercase{Table of Contents}}}
 		\addto\captionsenglish{\renewcommand{\refname}{\MakeTextUppercase{References}}}