# How can I make the apa6-document class NOT print a short title?

I am writing my master's thesis on TeXmaker. As for following the APA citation rules, I started using the apa6 document class. But even in the doc-mode, it still puts a short title (in capital letters) on top of every page, but I don't think that is appropriate in a master's thesis.
So my question is: how can I either erase that short title so it doesn't appear at all, or at least change it into normal letters? I tried \renewcommand{\shorttitle}[1]{} which I found in this forum, it seems to work for suppressing the abstract, but it didn't work for me.

I found a nice workaround: just leaving the \shorttitle{} -command empty helped. My MWE:

\documentclass[12pt,a4paper,doc]{apa6}
\usepackage[english, ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}

\begin{document}

\title{title}
\author{C.Zet}
\affiliation{master's thesis}
\date{\today}
\shorttitle{ }
\maketitle
\end{document}

• it doesn't work. the doc still says "Running head:" Sep 10 '18 at 19:23