diff --git a/documentation/docs/book.toml b/documentation/docs/book.toml
index 093c35eea0..a11f82cbbd 100644
--- a/documentation/docs/book.toml
+++ b/documentation/docs/book.toml
@@ -6,6 +6,9 @@ language = "en"
 multilingual = false # for the moment - ideally work on chinese, brazillian, spanish next
 src = "src"
 
+[rust]
+edition = "2018"
+
 #################
 # PREPROCESSORS #
 #################
@@ -42,7 +45,7 @@ turn-off = true
 
 [preprocessor.admonish]
 command = "mdbook-admonish"
-assets_version = "3.0.0" # do not edit: managed by `mdbook-admonish install`
+assets_version = "2.0.1" # do not edit: managed by `mdbook-admonish install`
 
 # variables preprocessor: import variables into files
 # https://gitlab.com/tglman/mdbook-variables/