diff --git a/src/data_structures/union_find.ml b/src/data_structures/union_find.ml
index 519c8676..434c53eb 100644
--- a/src/data_structures/union_find.ml
+++ b/src/data_structures/union_find.ml
@@ -47,51 +47,47 @@ module Make (X : VariableType) : S with type key = X.t = struct
   type key = X.t
 
   type 'a node =
-    { aliases : SX.t;
-      cardinal : int;
-      datum : 'a option
+    { aliases : SX.t
+    ; cardinal : int
+    ; datum : 'a option
     }
 
   type 'a t =
-    { canonical_elements : X.t MX.t;
-      node_of_canonicals : 'a node MX.t
+    { canonical_elements : X.t MX.t
+    ; node_of_canonicals : 'a node MX.t
     }
 
   let print_set ppf set =
-    if SX.is_empty set
-    then Format.fprintf ppf "{}"
+    if SX.is_empty set then Fmt.pf ppf "{}"
     else (
-      Format.fprintf ppf "@[<hov 1>{";
+      Fmt.pf ppf "@[<hov 1>{";
       let first = ref true in
       SX.iter
         (fun x ->
-          if !first then first := false else Format.fprintf ppf ",@ ";
-          X.print ppf x)
+          if !first then first := false else Fmt.pf ppf ",@ ";
+          X.print ppf x )
         set;
-      Format.fprintf ppf "}@]")
+      Fmt.pf ppf "}@]" )
 
   let print_map pp ppf map =
-    if MX.is_empty map
-    then Format.fprintf ppf "{}"
+    if MX.is_empty map then Fmt.pf ppf "{}"
     else (
-      Format.fprintf ppf "@[<hov 1>{";
+      Fmt.pf ppf "@[<hov 1>{";
       let first = ref true in
       MX.iter
         (fun key value ->
-          if !first then first := false else Format.fprintf ppf ",@ ";
-          Format.fprintf ppf "@[<hov 1>(%a@ %a)@]" X.print key pp value)
+          if !first then first := false else Fmt.pf ppf ",@ ";
+          Fmt.pf ppf "@[<hov 1>(%a@ %a)@]" X.print key pp value )
         map;
-      Format.fprintf ppf "}@]")
+      Fmt.pf ppf "}@]" )
 
   let print_aliases ppf { aliases; _ } = print_set ppf aliases
 
   let print_datum pp ppf { datum; _ } =
-    Format.pp_print_option
-      ~none:(fun ppf () -> Format.fprintf ppf "<default>")
-      pp ppf datum
+    Fmt.option ~none:(fun ppf () -> Fmt.pf ppf "<default>") pp ppf datum
 
   let[@ocamlformat "disable"] print pp ppf { node_of_canonicals; _ } =
-    Format.fprintf ppf
+    Fmt.pf ppf
       "@[<hov 1>(\
         @[<hov 1>(aliases_of_canonicals@ %a)@]@ \
         @[<hov 1>(payload_of_canonicals@ %a)@]\
@@ -109,18 +105,18 @@ module Make (X : VariableType) : S with type key = X.t = struct
   let add ~merge variable datum t =
     let variable = find_canonical variable t in
     let node_of_canonicals =
-      MX.update variable (function
-        | None ->
-          Some { aliases = SX.empty ; cardinal = 0 ; datum = Some datum }
-        | Some node ->
-          let datum =
-            match node.datum with
-            | None -> Some datum
-            | Some existing_datum ->
-              Some (merge datum existing_datum)
-          in
-          Some { node with datum })
-      t.node_of_canonicals
+      MX.update variable
+        (function
+          | None ->
+            Some { aliases = SX.empty; cardinal = 0; datum = Some datum }
+          | Some node ->
+            let datum =
+              match node.datum with
+              | None -> Some datum
+              | Some existing_datum -> Some (merge datum existing_datum)
+            in
+            Some { node with datum } )
+        t.node_of_canonicals
     in
     { t with node_of_canonicals }
 
@@ -128,7 +124,7 @@ module Make (X : VariableType) : S with type key = X.t = struct
 
   let find_node canonical t =
     match find_node_opt canonical t with
-    | None -> { aliases = SX.empty ; cardinal = 0 ; datum = None }
+    | None -> { aliases = SX.empty; cardinal = 0; datum = None }
     | Some node -> node
 
   let find_opt variable t =
@@ -138,39 +134,36 @@ module Make (X : VariableType) : S with type key = X.t = struct
 
   let set_canonical_element aliases canonical canonical_elements =
     SX.fold
-      (fun alias canonical_elements ->
-        MX.add alias canonical canonical_elements)
+      (fun alias canonical_elements -> MX.add alias canonical canonical_elements)
       aliases canonical_elements
 
   let union ~merge lhs rhs t =
     let lhs = find_canonical lhs t in
     let rhs = find_canonical rhs t in
-    if X.equal lhs rhs
-    then t
+    if X.equal lhs rhs then t
     else
       let lhs_node = find_node lhs t in
       let rhs_node = find_node rhs t in
       let demoted, canonical, canonical_elements =
-        if lhs_node.cardinal < rhs_node.cardinal
-        then
-          ( lhs,
-            rhs,
-            set_canonical_element lhs_node.aliases rhs t.canonical_elements )
+        if lhs_node.cardinal < rhs_node.cardinal then
+          ( lhs
+          , rhs
+          , set_canonical_element lhs_node.aliases rhs t.canonical_elements )
         else
-          ( rhs,
-            lhs,
-            set_canonical_element rhs_node.aliases lhs t.canonical_elements )
+          ( rhs
+          , lhs
+          , set_canonical_element rhs_node.aliases lhs t.canonical_elements )
       in
       let datum =
-        match lhs_node.datum, rhs_node.datum with
+        match (lhs_node.datum, rhs_node.datum) with
         | None, None -> None
         | None, Some datum | Some datum, None -> Some datum
         | Some lhs_datum, Some rhs_datum -> Some (merge lhs_datum rhs_datum)
       in
       let node =
-        { aliases = SX.union lhs_node.aliases rhs_node.aliases;
-          cardinal = lhs_node.cardinal + rhs_node.cardinal + 1;
-          datum
+        { aliases = SX.union lhs_node.aliases rhs_node.aliases
+        ; cardinal = lhs_node.cardinal + rhs_node.cardinal + 1
+        ; datum
         }
       in
       let node_of_canonicals = MX.add canonical node t.node_of_canonicals in
diff --git a/src/dune b/src/dune
index 7a1484d4..794fbce9 100644
--- a/src/dune
+++ b/src/dune
@@ -99,6 +99,7 @@
   tracing
   trap
   types
+  union_find
   value_intf
   v
   wasm_ffi_intf