diff --git a/calculus.tex b/calculus.tex
index 4d8046d..d599afe 100644
--- a/calculus.tex
+++ b/calculus.tex
@@ -1,4 +1,4 @@
-\documentclass[12pt,a4paper]{article}
+\documentclass[a4paper]{article}
 \mathchardef\ordinarycolon\mathcode`\:
 \mathcode`\:=\string"8000
 \begingroup \catcode`\:=\active