diff --git a/languages.toml b/languages.toml
index eff4ca062..7ffc998b8 100644
--- a/languages.toml
+++ b/languages.toml
@@ -1079,6 +1079,8 @@ comment-token = "--"
 block-comment-tokens = { start = "/-", end = "-/" }
 language-servers = [ "lean" ]
 indent = { tab-width = 2, unit = "  " }
+rulers = [101]
+text-width = 100
 
 [language.auto-pairs]
 '(' = ')'