diff --git a/README.md b/README.md
index f3b67ea..6e5a467 100644
--- a/README.md
+++ b/README.md
@@ -64,7 +64,6 @@ Take the following steps to build the Lean project:
 
 Optionally, you can:
 
-// 1. Run `lake build Book` to build all proofs in the first book of Euclid's *Elements* (takes a few minutes)
 1. Run `lake -R -Kenv=dev build SystemE:docs` to build the documentation
 1. View the auto-generated documentation locally at ./lake/build/doc, e.g., using `python -mhttp.server`