diff --git a/main.tex b/main.tex
index 47db85d..5df704a 100644
--- a/main.tex
+++ b/main.tex
@@ -1,4 +1,8 @@
-\documentclass[oneside]{scrbook}
+\documentclass[
+  10pt,
+  a4paper,
+  oneside
+]{scrbook}
 
 % Deal with overfull lines.
 % https://texfaq.org/FAQ-overfull