diff --git a/book/copyright/chapter.tex b/book/copyright/chapter.tex
index b17ef96..475f2cb 100644
--- a/book/copyright/chapter.tex
+++ b/book/copyright/chapter.tex
@@ -1,6 +1,6 @@
 \thispagestyle{plain}
 
-Copyright \copyright\ 2018 John Winans 
+Copyright \copyright\ 2018, 2019, 2020 John Winans 
 
 This document is made available under a Creative Commons Attribution 4.0 
 International License.  See \autoref{license} for more information.