diff --git a/.config/kak/autoload/filetype/mermaid.kak b/.config/kak/autoload/filetype/mermaid.kak
index 4c64d1dc..5c37a363 100644
--- a/.config/kak/autoload/filetype/mermaid.kak
+++ b/.config/kak/autoload/filetype/mermaid.kak
@@ -1,3 +1,17 @@
 hook global BufCreate .+[.](mmd|mermaid) %{
     set-option buffer filetype mermaid
 }
+
+hook global WinSetOption filetype=mermaid %{
+    require-module mermaid
+    set-option window indentwidth 2
+    set-option window comment_line '%%'
+}
+
+provide-module mermaid %—
+    define-command -hidden mermaid-indent-on-new-line %~
+        # preserve prev line indent
+        try %{ execute-keys -draft <semicolon> K <a-&> }
+    ~
+
+—