diff --git a/src/HsH-article.cls b/src/HsH-article.cls
index f1de34f86a8121a2a6d20fab9be0d6a27c3a3489..fb60a3981fb4ad1f27eacd8ee601e2111308363d 100644
--- a/src/HsH-article.cls
+++ b/src/HsH-article.cls
@@ -5,21 +5,21 @@
 %% The original source files were:
 %%
 %% HsH-classes.dtx  (with options: `article')
-%% 
+%%
 %% This is a generated file.
-%% 
+%%
 %% Copyright (C) 2021 by Jan Wille <mail@janwille.de>
-%% 
+%%
 %% This file may be distributed and/or modified under the conditions of
 %% the LaTeX Project Public License, either version 1.3 of this license
 %% or (at your option) any later version.  The latest version of this
 %% license is in:
-%% 
+%%
 %%    http://www.latex-project.org/lppl.txt
-%% 
+%%
 %% and version 1.3 or later is part of all distributions of LaTeX version
 %% 2021/01/01 or later.
-%% 
+%%
 \typeout{Adapted from KOMA script for use in Hochschule Hannover <2021-04-21> Jan Wille}
 \NeedsTeXFormat{LaTeX2e}
 \newcommand{\myClassName}{HsH-article}
@@ -62,7 +62,7 @@
 \DeclareOption{roman}{
   \renewcommand{\familydefault}{\rmdefault}
 }
-\DeclareOption*{\PassOptionsToClass{\CurrentOption}{scrartcl}}
+\DeclareOption*{\expandafter\PassOptionsToClass\expandafter{\CurrentOption}{scrartcl}}
 \ExecuteOptions{fontsize=11pt,a4paper,ngerman,sans} % default options
 \ProcessOptions\relax
 %% Load KOMA class
@@ -95,7 +95,7 @@
 \RequirePackage{pgffor}
 %% options for not loaded packages ----------------------------------------------------------------
 \PassOptionsToPackage{backend=biber,style=alphabetic,sorting=nyt}{biblatex}
-\PassOptionsToPackage{free-standing-units,abbreviations}{siunitx}
+\PassOptionsToPackage{free-standing-units}{siunitx}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 
 %% title matters ----------------------------------------------------------------------------------
diff --git a/src/HsH-report.cls b/src/HsH-report.cls
index e04f7520ce9e2f7309d67363a7bbee545e5c83d3..393435cedd36543578d5f774c7469c10376dffba 100644
--- a/src/HsH-report.cls
+++ b/src/HsH-report.cls
@@ -5,21 +5,21 @@
 %% The original source files were:
 %%
 %% HsH-classes.dtx  (with options: `report')
-%% 
+%%
 %% This is a generated file.
-%% 
+%%
 %% Copyright (C) 2021 by Jan Wille <mail@janwille.de>
-%% 
+%%
 %% This file may be distributed and/or modified under the conditions of
 %% the LaTeX Project Public License, either version 1.3 of this license
 %% or (at your option) any later version.  The latest version of this
 %% license is in:
-%% 
+%%
 %%    http://www.latex-project.org/lppl.txt
-%% 
+%%
 %% and version 1.3 or later is part of all distributions of LaTeX version
 %% 2021/01/01 or later.
-%% 
+%%
 \typeout{Adapted from KOMA script for use in Hochschule Hannover <2021-04-21> Jan Wille}
 \NeedsTeXFormat{LaTeX2e}
 \newcommand{\myClassName}{HsH-report}
@@ -62,7 +62,7 @@
 \DeclareOption{roman}{
   \renewcommand{\familydefault}{\rmdefault}
 }
-\DeclareOption*{\PassOptionsToClass{\CurrentOption}{scrreprt}}
+\DeclareOption*{\expandafter\PassOptionsToClass\expandafter{\CurrentOption}{scrreprt}}
 \ExecuteOptions{fontsize=11pt,a4paper,ngerman,sans} % default options
 \ProcessOptions\relax
 %% Load KOMA class
@@ -95,7 +95,7 @@
 \RequirePackage{pgffor}
 %% options for not loaded packages ----------------------------------------------------------------
 \PassOptionsToPackage{backend=biber,style=alphabetic,sorting=nyt}{biblatex}
-\PassOptionsToPackage{free-standing-units,abbreviations}{siunitx}
+\PassOptionsToPackage{free-standing-units}{siunitx}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 
 %% title matters ----------------------------------------------------------------------------------
diff --git a/src/HsH-standalone.cls b/src/HsH-standalone.cls
index 2ae116dd0c899d2453f335ba34094fff50d5d6bb..d2c4e8c3ed55ff83023509a8ebeca1817a5970a1 100644
--- a/src/HsH-standalone.cls
+++ b/src/HsH-standalone.cls
@@ -5,21 +5,21 @@
 %% The original source files were:
 %%
 %% HsH-classes.dtx  (with options: `standalone')
-%% 
+%%
 %% This is a generated file.
-%% 
+%%
 %% Copyright (C) 2021 by Jan Wille <mail@janwille.de>
-%% 
+%%
 %% This file may be distributed and/or modified under the conditions of
 %% the LaTeX Project Public License, either version 1.3 of this license
 %% or (at your option) any later version.  The latest version of this
 %% license is in:
-%% 
+%%
 %%    http://www.latex-project.org/lppl.txt
-%% 
+%%
 %% and version 1.3 or later is part of all distributions of LaTeX version
 %% 2021/01/01 or later.
-%% 
+%%
 \typeout{Adapted from KOMA script for use in Hochschule Hannover <2021-04-21> Jan Wille}
 \NeedsTeXFormat{LaTeX2e}
 \newcommand{\myClassName}{HsH-standalone}
@@ -62,7 +62,7 @@
 \DeclareOption{roman}{
   \renewcommand{\familydefault}{\rmdefault}
 }
-\DeclareOption*{\PassOptionsToClass{\CurrentOption}{standalone}}
+\DeclareOption*{\expandafter\PassOptionsToClass\expandafter{\CurrentOption}{standalone}}
 \ExecuteOptions{margin=0.25cm,fontsize=11pt,a4paper,ngerman,sans} % default options
 \ProcessOptions\relax
 %% Load KOMA class
@@ -78,7 +78,7 @@
 \RequirePackage{amsmath}
 \if@german\RequirePackage{ziffer}\fi
 %% options for not loaded packages ----------------------------------------------------------------
-\PassOptionsToPackage{free-standing-units,abbreviations}{siunitx}
+\PassOptionsToPackage{free-standing-units}{siunitx}
 \PassOptionsToPackage{european,EFvoltages,straightvoltages,betterproportions}{circuitikz}
 
 %% typesetting indexes upright or standart