diff --git a/slides/chapter-11.de.md b/slides/chapter-11.de.md
index 3e3727e..7a73856 100644
--- a/slides/chapter-11.de.md
+++ b/slides/chapter-11.de.md
@@ -67,7 +67,7 @@ Themen und Stile
     breaklines=true,
     keywordstyle=\color{ForestGreen},
     commentstyle=\color{DarkGray},
-    literate={ö}{{\"o}}
+    literate={ö}{{\"o}}1
 ]
 % …
 \end{lstlisting}
diff --git a/slides/chapter-11.en.md b/slides/chapter-11.en.md
index 496389e..5435448 100644
--- a/slides/chapter-11.en.md
+++ b/slides/chapter-11.en.md
@@ -67,7 +67,7 @@ Themes and styles
     breaklines=true,
     keywordstyle=\color{ForestGreen},
     commentstyle=\color{DarkGray},
-    literate={ö}{{\"o}}
+    literate={ö}{{\"o}}1
 ]
 % …
 \end{lstlisting}