diff --git a/languages.toml b/languages.toml
index 436937cd86cc..8f60f9d0c638 100644
--- a/languages.toml
+++ b/languages.toml
@@ -1078,6 +1078,8 @@ comment-token = "--"
 block-comment-tokens = { start = "/-", end = "-/" }
 language-servers = [ "lean" ]
 indent = { tab-width = 2, unit = "  " }
+rulers = [101]
+text-width = 100
 
 [language.auto-pairs]
 '(' = ')'