diff --git a/book.toml b/book.toml
index e37b56a8d4..24275dc61c 100644
--- a/book.toml
+++ b/book.toml
@@ -24,9 +24,3 @@ git-repository-url = "https://github.com/vector-im/element-web"
 
 # The path that the docs are hosted on
 site-url = "/element-web/"
-additional-js = ["mermaid.min.js", "mermaid-init.js"]
-
-[preprocessor]
-
-[preprocessor.mermaid]
-command = "mdbook-mermaid"