diff --git a/src/HsH-article.cls b/src/HsH-article.cls
index abb5657735105c1e84c28a3a2ab59a9895e55d50..07cf0e6a21402bf3748932c6cfaa020a5c723915 100644
--- a/src/HsH-article.cls
+++ b/src/HsH-article.cls
@@ -5,16 +5,16 @@
 %% The original source files were:
 %%
 %% HsH-classes.dtx  (with options: `article')
-%%
+%% 
 %% Copyright (C) 2024 by Jan Wille <mail@janiwlle.de>
-%%
+%% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License (LPPL), either
 %% version 1.3c of this license or (at your option) any later
 %% version.  The latest version of this license is in the file:
-%%
+%% 
 %% http://www.latex-project.org/lppl.txt
-%%
+%% 
 \NeedsTeXFormat{LaTeX2e}[2022-06-01]
 \ProvidesClass{HsH-article}
     [2024-04-23 3.00 HsH-class based on KOMA]
@@ -171,7 +171,7 @@
 \RequirePackage[main=\HsH@opt@language]{babel}
 \RequirePackage[autostyle=true]{csquotes}
 \MakeOuterQuote{"}
-\iflanguage{ngerman}{\RequirePackage{ziffer}}{}%
+\iflanguage{ngerman}{\RequirePackage{ziffer}}{}
 \RequirePackage[hidelinks]{hyperref} % must load before `bookmarks'
 \RequirePackage{bookmark}
 \AtBeginDocument{
@@ -199,7 +199,6 @@
 \RequirePackage{graphicx}
 \RequirePackage{amsmath,amssymb,amsfonts}
 \RequirePackage[svgnames]{xcolor}
-\RequirePackage{scrhack}
 \PassOptionsToPackage{backend=biber}{biblatex}
 \AtBeginDocument{
   \makeatletter
@@ -209,6 +208,26 @@
   \makeatother
 }
 \PassOptionsToPackage{free-standing-units}{siunitx}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{siunitx}{
+    \iflanguage{ngerman}{
+      \sisetup{output-decimal-marker={,}}
+    }{}
+  }{}
+  \makeatother
+}
+\RequirePackage{scrhack}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{biblatex}{
+    \RequirePackage{lstautogobble}\lstset{autogobble=true}
+    \iflanguage{ngerman}{
+      \lstset{literate={Ö}{{\"O}}1{Ä}{{\"A}}1{Ü}{{\"U}}1{ß}{{\ss}}1{ü}{{\"u}}1{ä}{{\"a}}1{ö}{{\"o}}1}
+    }{}
+  }{}
+  \makeatother
+}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 \AtBeginDocument{
   \makeatletter
diff --git a/src/HsH-classes.cfg b/src/HsH-classes.cfg
index c3a352fba9e26336ecd68211e67d8b836f91a191..5b8947308fc113ed485cc42017513af8af1561a1 100644
--- a/src/HsH-classes.cfg
+++ b/src/HsH-classes.cfg
@@ -14,9 +14,6 @@
   }
 }{}
 \@ifpackageloaded{siunitx}{
-  \iflanguage{ngerman}{
-    \sisetup{output-decimal-marker={,}} % use comma as dezimal
-  }{}%
   \sisetup{
     tight-spacing=true,
     per-mode=symbol,
@@ -27,9 +24,6 @@
   }
 }{}
 \@ifpackageloaded{listings}{
-  \PassOptionsToPackage{svgnames}{xcolor}
-  \RequirePackage{xcolor}
-  \RequirePackage{lstautogobble}
   \lstset{
     commentstyle=\color{gray},
     keywordstyle=\color{FireBrick}\bfseries,
@@ -37,9 +31,7 @@
     showstringspaces=false,
     basicstyle=\ttfamily,
     tabsize=4,
-    literate={Ö}{{\"O}}1{Ä}{{\"A}}1{Ü}{{\"U}}1{ß}{{\ss}}1{ü}{{\"u}}1{ä}{{\"a}}1{ö}{{\"o}}1,
     escapeinside={(*@}{@*)},
-    autogobble=true,
   }
 }{}
 \@ifpackageloaded{enumitem}{
diff --git a/src/HsH-classes.dtx b/src/HsH-classes.dtx
index 13cf50c6d4aa6ffcb197c81fdf9dd5bf503cdaaf..24148ae1f2d9f9eaad9673d57bbf21c05be2d3dd 100644
--- a/src/HsH-classes.dtx
+++ b/src/HsH-classes.dtx
@@ -861,7 +861,7 @@ http://www.latex-project.org/lppl.txt
 %      replacing it with some whitespace on printed version. Luckily loading the
 %      \pkg{ziffer} package sets this up to match the german standart.
 %    \begin{macrocode}
-\iflanguage{ngerman}{\RequirePackage{ziffer}}{}%
+\iflanguage{ngerman}{\RequirePackage{ziffer}}{}
 %    \end{macrocode}
 %
 %
@@ -908,12 +908,6 @@ http://www.latex-project.org/lppl.txt
 \RequirePackage[svgnames]{xcolor}
 %    \end{macrocode}
 %
-%      For better compatibility with the \pkg{listings} package we load the
-%      \pkg{scrhack} package.
-%    \begin{macrocode}
-\RequirePackage{scrhack}
-%    \end{macrocode}
-%
 %    \subsubsection{Options for packages that could be loaded by the user}
 %      Some package are not always needed and potentially heavy to load in by default.
 %      But its still usefull to set default options for these packagese.
@@ -921,6 +915,9 @@ http://www.latex-project.org/lppl.txt
 %      These differ from the settings provided in |HsH-classes.cfg| in that they are
 %      defaults that apply allway and not user-configurable preferences which are user
 %      or even project specific.
+%
+%      For the \pkg{bibtex} we ensure the \emph{biber} backend is selcted, which matches
+%      the settings in |.latexmkrc|.
 %    \begin{macrocode}
 %<*article|report>
 \PassOptionsToPackage{backend=biber}{biblatex}
@@ -932,7 +929,41 @@ http://www.latex-project.org/lppl.txt
   \makeatother
 }
 %</article|report>
+%    \end{macrocode}
+%
+%      For \pkg{bibtex} we load the free-stadnding units, mostly for backwards compatibility.
+%      We also ensure german language specific settings are applyed.
+%    \begin{macrocode}
 \PassOptionsToPackage{free-standing-units}{siunitx}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{siunitx}{
+    \iflanguage{ngerman}{
+      \sisetup{output-decimal-marker={,}}
+    }{}
+  }{}
+  \makeatother
+}
+%    \end{macrocode}
+%
+%      For better compatibility with the \pkg{listings} package we load the
+%      \pkg{scrhack} package. We also pass some configurations to if if it gets loaded.
+%    \begin{macrocode}
+\RequirePackage{scrhack}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{biblatex}{
+    \RequirePackage{lstautogobble}\lstset{autogobble=true}
+    \iflanguage{ngerman}{
+      \lstset{literate={Ö}{{\"O}}1{Ä}{{\"A}}1{Ü}{{\"U}}1{ß}{{\ss}}1{ü}{{\"u}}1{ä}{{\"a}}1{ö}{{\"o}}1}
+    }{}
+  }{}
+  \makeatother
+}
+%    \end{macrocode}
+%
+%      The \pkg{circuitikz} needs bo be configure so it matches typical european styles.
+%    \begin{macrocode}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 %    \end{macrocode}
 %
diff --git a/src/HsH-classes.pdf b/src/HsH-classes.pdf
index 593cecaf0968943fa3e2613563162ab220ae10f0..c46cf0c68a01ff07c208adcea73db768c3f002e4 100644
--- a/src/HsH-classes.pdf
+++ b/src/HsH-classes.pdf
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:9fc4c73ce94b87b806dc3dab2f1d830277c372596b61e94d7c72ee647905a2f4
-size 310671
+oid sha256:5511976d0dbcde0b1cf2b63aaf4467734dc03f8c8574781d19cc506504445c63
+size 312970
diff --git a/src/HsH-report.cls b/src/HsH-report.cls
index e80866519a9880d064b5055b59a9e79af9d165fe..3548b21bd5f3128dae2cbc6383000e43bf138199 100644
--- a/src/HsH-report.cls
+++ b/src/HsH-report.cls
@@ -5,16 +5,16 @@
 %% The original source files were:
 %%
 %% HsH-classes.dtx  (with options: `report')
-%%
+%% 
 %% Copyright (C) 2024 by Jan Wille <mail@janiwlle.de>
-%%
+%% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License (LPPL), either
 %% version 1.3c of this license or (at your option) any later
 %% version.  The latest version of this license is in the file:
-%%
+%% 
 %% http://www.latex-project.org/lppl.txt
-%%
+%% 
 \NeedsTeXFormat{LaTeX2e}[2022-06-01]
 \ProvidesClass{HsH-report}
     [2024-04-23 3.00 HsH-class based on KOMA]
@@ -171,7 +171,7 @@
 \RequirePackage[main=\HsH@opt@language]{babel}
 \RequirePackage[autostyle=true]{csquotes}
 \MakeOuterQuote{"}
-\iflanguage{ngerman}{\RequirePackage{ziffer}}{}%
+\iflanguage{ngerman}{\RequirePackage{ziffer}}{}
 \RequirePackage[hidelinks]{hyperref} % must load before `bookmarks'
 \RequirePackage{bookmark}
 \AtBeginDocument{
@@ -199,7 +199,6 @@
 \RequirePackage{graphicx}
 \RequirePackage{amsmath,amssymb,amsfonts}
 \RequirePackage[svgnames]{xcolor}
-\RequirePackage{scrhack}
 \PassOptionsToPackage{backend=biber}{biblatex}
 \AtBeginDocument{
   \makeatletter
@@ -209,6 +208,26 @@
   \makeatother
 }
 \PassOptionsToPackage{free-standing-units}{siunitx}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{siunitx}{
+    \iflanguage{ngerman}{
+      \sisetup{output-decimal-marker={,}}
+    }{}
+  }{}
+  \makeatother
+}
+\RequirePackage{scrhack}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{biblatex}{
+    \RequirePackage{lstautogobble}\lstset{autogobble=true}
+    \iflanguage{ngerman}{
+      \lstset{literate={Ö}{{\"O}}1{Ä}{{\"A}}1{Ü}{{\"U}}1{ß}{{\ss}}1{ü}{{\"u}}1{ä}{{\"a}}1{ö}{{\"o}}1}
+    }{}
+  }{}
+  \makeatother
+}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 \AtBeginDocument{
   \makeatletter
diff --git a/src/HsH-standalone.cls b/src/HsH-standalone.cls
index cfcfa1540c5a0c0f20b548c01fcd68afe35a6d22..04decc2c31f8364c5c497209c8a53f923cb3a96e 100644
--- a/src/HsH-standalone.cls
+++ b/src/HsH-standalone.cls
@@ -5,16 +5,16 @@
 %% The original source files were:
 %%
 %% HsH-classes.dtx  (with options: `standalone')
-%%
+%% 
 %% Copyright (C) 2024 by Jan Wille <mail@janiwlle.de>
-%%
+%% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License (LPPL), either
 %% version 1.3c of this license or (at your option) any later
 %% version.  The latest version of this license is in the file:
-%%
+%% 
 %% http://www.latex-project.org/lppl.txt
-%%
+%% 
 \NeedsTeXFormat{LaTeX2e}[2022-06-01]
 \ProvidesClass{HsH-standalone}
     [2024-04-23 3.00 HsH-class based on KOMA]
@@ -104,7 +104,7 @@
 \RequirePackage[main=\HsH@opt@language]{babel}
 \RequirePackage[autostyle=true]{csquotes}
 \MakeOuterQuote{"}
-\iflanguage{ngerman}{\RequirePackage{ziffer}}{}%
+\iflanguage{ngerman}{\RequirePackage{ziffer}}{}
 \RequirePackage[hidelinks]{hyperref} % must load before `bookmarks'
 \RequirePackage{bookmark}
 \AtBeginDocument{
@@ -132,8 +132,27 @@
 \RequirePackage{graphicx}
 \RequirePackage{amsmath,amssymb,amsfonts}
 \RequirePackage[svgnames]{xcolor}
-\RequirePackage{scrhack}
 \PassOptionsToPackage{free-standing-units}{siunitx}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{siunitx}{
+    \iflanguage{ngerman}{
+      \sisetup{output-decimal-marker={,}}
+    }{}
+  }{}
+  \makeatother
+}
+\RequirePackage{scrhack}
+\AtBeginDocument{
+  \makeatletter
+  \@ifpackageloaded{biblatex}{
+    \RequirePackage{lstautogobble}\lstset{autogobble=true}
+    \iflanguage{ngerman}{
+      \lstset{literate={Ö}{{\"O}}1{Ä}{{\"A}}1{Ü}{{\"U}}1{ß}{{\ss}}1{ü}{{\"u}}1{ä}{{\"a}}1{ö}{{\"o}}1}
+    }{}
+  }{}
+  \makeatother
+}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 \AtBeginDocument{
   \makeatletter
diff --git a/test.pdf b/test.pdf
index bcb14ffd00546c305ea11344c312e6a80d0129d2..e849b842d637608515e1fc038d2b25248ce31ff8 100644
--- a/test.pdf
+++ b/test.pdf
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:9d5d9728aa5d9aec8d3dade86e36576ddc5b5bbbb44c71e5f2e0d3bf72e8c0a5
-size 192319
+oid sha256:840ea5ae3c85ee50216c6d560b7c9cdd83562b569a438ee6ff26d264d5387f96
+size 193375
diff --git a/test.tex b/test.tex
index 7c43a7b3ead61141fb1e03b8cb802658695c87a9..64a6726bb52f3d45a5d3808e05db05dd127787cf 100644
--- a/test.tex
+++ b/test.tex
@@ -1,6 +1,7 @@
 \documentclass[todos=off]{HsH-report}
 
 \usepackage{lipsum}
+\usepackage{siunitx}
 % \usepackage{showframe}
 
 %% documents personal data:
@@ -40,6 +41,11 @@
 			A_1 = \sum_{i=0}^{10} B_i + \abs{\frac{x}{2}}
 		\end{equation}
 
+		\begin{equation}
+			\frac{4\,\m}{12\,\s} = \frac{1}{3}\,\unit{m\per s}
+		\end{equation}
+
+
 		\begin{itemize}
 			\item Hello World
 			\item test