diff --git a/dune b/dune
index af1fdb08..1b55029c 100644
--- a/dune
+++ b/dune
@@ -1 +1,8 @@
 (data_only_dirs tests)
+
+(env
+ (_
+  (flags :standard -warn-error -a+8+9 -w +a-4-32-40-41-42-44-48-70 -color
+    always -strict-sequence -safe-string -short-paths)
+  (ocamlopt_flags :standard -O3 -color always -unbox-closures
+    -unbox-closures-factor 20)))
diff --git a/sidekick.opam b/sidekick.opam
index c9da08f3..49f9e558 100644
--- a/sidekick.opam
+++ b/sidekick.opam
@@ -21,6 +21,7 @@ depends: [
 ]
 depopts: [
   "mtime"   # for profiling stuff
+  "memtrace" # memory profiling
   "zarith" # for arithmetic
 ]
 conflicts: [
diff --git a/src/base/Proof.ml b/src/base/Proof.ml
index 6f243a84..8cca974b 100644
--- a/src/base/Proof.ml
+++ b/src/base/Proof.ml
@@ -46,11 +46,10 @@ type term = Term.t
 
 type t = {
   mutable enabled : bool;
-  config: Config.t;
   buf: Buffer.t;
   out: Proof_ser.Bare.Encode.t;
   mutable storage: Storage.t;
-  mutable dispose: unit -> unit;
+  dispose: unit -> unit;
   mutable steps_writer: CS.Writer.t;
   mutable next_id: int;
   map_term: term_id Term.Tbl.t; (* term -> proof ID *)
@@ -91,12 +90,12 @@ let create ?(config=Config.default) () : t =
       let dispose () = close_out oc in
       Storage.On_disk (file, oc), w, dispose
   in
-  let buf = Buffer.create 1024 in
+  let buf = Buffer.create 1_024 in
+  let out = Proof_ser.Bare.Encode.of_buffer buf in
   { enabled=config.Config.enabled;
-    config;
     next_id=1;
     buf;
-    out=Proof_ser.Bare.Encode.of_buffer buf;
+    out;
     map_term=Term.Tbl.create 32;
     map_fun=Fun.Tbl.create 32;
     steps_writer; storage; dispose;
diff --git a/src/dune b/src/dune
deleted file mode 100644
index 17d9707a..00000000
--- a/src/dune
+++ /dev/null
@@ -1,7 +0,0 @@
-
-(env
-  (_
-    (flags :standard -warn-error
-           -a+8+9 -w +a-4-32-40-41-42-44-48
-           -color always -strict-sequence -safe-string -short-paths)
-    (ocamlopt_flags :standard -O3 -color always -unbox-closures -unbox-closures-factor 20)))