diff --git a/commun/commun.sty b/commun/commun.sty
index ec15415..6926c63 100644
--- a/commun/commun.sty
+++ b/commun/commun.sty
@@ -59,6 +59,7 @@
 \RequirePackage{amsmath}
 \RequirePackage{amssymb}
 \RequirePackage{tkz-euclide}
+\usetikzlibrary{shadows}
 \RequirePackage{calc}
 \RequirePackage{pgfplots}
 \RequirePackage{siunitx}