diff --git a/preamble.tex b/preamble.tex
index c428907..f2287dc 100644
--- a/preamble.tex
+++ b/preamble.tex
@@ -2,5 +2,8 @@
 
 \input{tikz/tikzpreamble.tex}
 
+\usepacckage{xcolor}
+\usepackage{tcolorbox}
+
 \definecolor{myteal}{HTML}{228c9c}
 \DeclareTColorBox{blockbox}{ O{width=\textwidth} }{boxrule=0mm, colframe=myteal, valign lower=bottom, on line, lower separated=false, height=.6\textheight, #1}