diff --git a/logarion.opam b/logarion.opam
index 09b696a..e6fc486 100644
--- a/logarion.opam
+++ b/logarion.opam
@@ -14,7 +14,6 @@ depends: [
   "uuidm"
   "omd"
   "opium"
-  "batteries"
   "lwt"
   "ptime"
   "re"
diff --git a/src/core/meta.ml b/src/core/meta.ml
index 65d8d3f..c11783f 100644
--- a/src/core/meta.ml
+++ b/src/core/meta.ml
@@ -88,16 +88,17 @@ let string_alias t =
   let is_reserved = function
     | '!' | '*' | '\'' | '(' | ')' | ';' | ':' | '@' | '&' | '=' | '+' | '$'
       | ',' | '/' | '?' | '#' | '[' | ']' | ' ' | '\t' | '\x00' -> true
-    | _ -> false in
-  let drop h t = t in
-  let dash h t = '-' :: t in
-  let rec filter fn = function
-    | [] -> []
-    | head :: tail ->
-       if is_reserved head
-       then fn head (filter drop tail)
-       else Char.lowercase_ascii head :: (filter dash tail) in
-  Batteries.String.of_list @@ filter drop (Batteries.String.to_list t)
+    | _ -> false
+  in
+  let b = Buffer.create (String.length t) in
+  let filter char =
+    let open Buffer in
+    if is_reserved char
+    then (try (if nth b (pred (length b)) <> '-' then add_char b '-') with Invalid_argument _ -> prerr_endline "reserved")
+    else add_char b char
+  in
+  String.iter filter t;
+  Buffer.contents b
 
 type t = {
     title: string;