diff --git a/preamble.tex b/preamble.tex
index 86a55fd..43d1a3c 100644
--- a/preamble.tex
+++ b/preamble.tex
@@ -1,2 +1,3 @@
 \usepackage{amsmath}
+\usepackage{url}
 \DeclareMathOperator*{\argmax}{argmax}
\ No newline at end of file