diff --git a/dune-project b/dune-project
index e345e90..30ad6a5 100644
--- a/dune-project
+++ b/dune-project
@@ -35,8 +35,7 @@
   irmin-fs
   ppx_irmin
   lwt
-  (melange
-   (= 5.0.1-53))
+  melange
   melange-fetch
   melange-json
   melange-json-native
diff --git a/output/src/client/App.js b/output/src/client/App.js
index ce1d2b0..68340f3 100644
--- a/output/src/client/App.js
+++ b/output/src/client/App.js
@@ -9,7 +9,7 @@ import * as React from "react";
 import * as JsxRuntime from "react/jsx-runtime";
 
 function App(Props) {
-  const url = Router.useUrl(undefined);
+  const url = Router.useUrl();
   const gameId = url.route;
   let tmp;
   tmp = /* tag */ typeof gameId === "number" || typeof gameId === "string" ? (
diff --git a/output/src/client/context/ConfirmContext.js b/output/src/client/context/ConfirmContext.js
index 0caf8b5..3d846f0 100644
--- a/output/src/client/context/ConfirmContext.js
+++ b/output/src/client/context/ConfirmContext.js
@@ -63,7 +63,7 @@ function ConfirmContext$Provider(Props) {
       const match = confirmDialog.onConfirm;
       confirmation = Curry._1(match[1], undefined);
     } else {
-      confirmation = Promise.resolve(undefined);
+      confirmation = Promise.resolve();
     }
     return confirmation.then(function (param) {
       Curry._1(setIsConfirming, (function (param) {
@@ -72,7 +72,7 @@ function ConfirmContext$Provider(Props) {
       Curry._1(setIsOpen, (function (param) {
         return false;
       }));
-      return Promise.resolve(undefined);
+      return Promise.resolve();
     });
   }), [
     confirmDialog,
diff --git a/output/src/client/router/Router.js b/output/src/client/router/Router.js
index 30d0ecd..92359de 100644
--- a/output/src/client/router/Router.js
+++ b/output/src/client/router/Router.js
@@ -135,7 +135,7 @@ function search(param) {
     case "?" :
       return "";
     default:
-      return raw.slice(1, undefined);
+      return raw.slice(1);
   }
 }
 
@@ -151,7 +151,7 @@ function getParam(key) {
     } else {
       return false;
     }
-  }), Stdlib__String.split_on_char(/* '&' */38, search(undefined)));
+  }), Stdlib__String.split_on_char(/* '&' */38, search()));
   if (param === undefined) {
     return;
   }
diff --git a/output/src/client/ui/components/Select/Select.js b/output/src/client/ui/components/Select/Select.js
index 3f200e8..18eccba 100644
--- a/output/src/client/ui/components/Select/Select.js
+++ b/output/src/client/ui/components/Select/Select.js
@@ -151,7 +151,7 @@ function Select$Single(Props) {
     const foundOption = options.find(function (option, index) {
       if (index >= startIndex && index < endIndex) {
         foundIndex.contents = index;
-        return option.text.toUpperCase().indexOf(keysSoFar.toUpperCase(), undefined) === 0;
+        return option.text.toUpperCase().indexOf(keysSoFar.toUpperCase()) === 0;
       } else {
         return false;
       }
@@ -230,7 +230,7 @@ function Select$Single(Props) {
         break;
       case "Home" :
         e.preventDefault();
-        return focusFirstItem(undefined);
+        return focusFirstItem();
       case "ArrowUp" :
       case "Up" :
         exit = 3;
@@ -310,7 +310,7 @@ function Select$Single(Props) {
     if (focusedOption !== undefined) {
       return;
     } else {
-      return focusFirstItem(undefined);
+      return focusFirstItem();
     }
   };
   let tmp;
@@ -546,7 +546,7 @@ function Select$Multi(Props) {
     const foundOption = options.find(function (option, index) {
       if (index >= startIndex && index < endIndex) {
         foundIndex.contents = index;
-        return option.text.toUpperCase().startsWith(keysSoFar.toUpperCase(), undefined);
+        return option.text.toUpperCase().startsWith(keysSoFar.toUpperCase());
       } else {
         return false;
       }
@@ -626,7 +626,7 @@ function Select$Multi(Props) {
         break;
       case "Home" :
         e.preventDefault();
-        return focusFirstItem(undefined);
+        return focusFirstItem();
       case "ArrowUp" :
       case "Up" :
         exit = 2;
@@ -700,7 +700,7 @@ function Select$Multi(Props) {
     if (focusedOption !== undefined) {
       return;
     } else {
-      return focusFirstItem(undefined);
+      return focusFirstItem();
     }
   };
   return JsxRuntime.jsxs("div", {
diff --git a/output/src/client/ui/patterns/GameBoard/GameBoard.js b/output/src/client/ui/patterns/GameBoard/GameBoard.js
index 3c573e3..e9f02ef 100644
--- a/output/src/client/ui/patterns/GameBoard/GameBoard.js
+++ b/output/src/client/ui/patterns/GameBoard/GameBoard.js
@@ -27,7 +27,7 @@ function GameBoard(Props) {
       
     })
   ];
-  const func = Curry._3(Hooks__Hooks_Confirm.useConfirm(undefined), "Not everyone voted", "There are some players that did not pick a card yet. Do you really want to reveal all cards?", "Warning");
+  const func = Curry._3(Hooks__Hooks_Confirm.useConfirm(), "Not everyone voted", "There are some players that did not pick a card yet. Do you really want to reveal all cards?", "Warning");
   const match = React.useState(function () {
     
   });
@@ -58,7 +58,7 @@ function GameBoard(Props) {
     
   };
   React.useEffect((function () {
-    const wsConnection = new WebSocket(Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.websocket(undefined)), gameId));
+    const wsConnection = new WebSocket(Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.websocket()), gameId));
     ws.current = Caml_option.some(wsConnection);
     wsConnection.addEventListener("message", (function (param) {
       const s = Shared_client__Websocket.response_of_json(JSON.parse(param.data));
diff --git a/output/src/client/ui/patterns/PlayGameHeader/PlayGameHeader.js b/output/src/client/ui/patterns/PlayGameHeader/PlayGameHeader.js
index 75d128a..7c7e7a3 100644
--- a/output/src/client/ui/patterns/PlayGameHeader/PlayGameHeader.js
+++ b/output/src/client/ui/patterns/PlayGameHeader/PlayGameHeader.js
@@ -31,7 +31,7 @@ function PlayGameHeader(Props) {
           danger: true,
           action: {
             NAME: "Href",
-            VAL: Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.leave_game(undefined)), game.id)
+            VAL: Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.leave_game()), game.id)
           },
           children: "Leave Game"
         }),
diff --git a/output/src/client/ui/screens/CreateGame.js b/output/src/client/ui/screens/CreateGame.js
index a167128..e9dd99e 100644
--- a/output/src/client/ui/screens/CreateGame.js
+++ b/output/src/client/ui/screens/CreateGame.js
@@ -23,7 +23,7 @@ function CreateGame(Props) {
       deck: deck$1,
       reveal: reveal
     }));
-    fetch(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.create_game(undefined)), Fetch.RequestInit.make(/* Post */ 2, undefined, Caml_option.some(data), undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined)(undefined)).then(function (prim) {
+    fetch(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.create_game()), Fetch.RequestInit.make(/* Post */ 2, undefined, Caml_option.some(data), undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined)()).then(function (prim) {
       return prim.json();
     }).then(function (data) {
       return Promise.resolve(Curry._1(Shared_client__Game.Api.Create.response_of_json, data));
diff --git a/output/src/client/ui/screens/JoinGame.js b/output/src/client/ui/screens/JoinGame.js
index 41f8e0a..2216262 100644
--- a/output/src/client/ui/screens/JoinGame.js
+++ b/output/src/client/ui/screens/JoinGame.js
@@ -19,7 +19,7 @@ function JoinGame(Props) {
       typ: typ,
       name: name
     }));
-    fetch(Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.join_game(undefined)), gameId), Fetch.RequestInit.make(/* Post */ 2, undefined, Caml_option.some(data), undefined, undefined, undefined, /* SameOrigin */ 1, undefined, undefined, undefined, undefined, undefined)(undefined)).then(function (param) {
+    fetch(Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.join_game()), gameId), Fetch.RequestInit.make(/* Post */ 2, undefined, Caml_option.some(data), undefined, undefined, undefined, /* SameOrigin */ 1, undefined, undefined, undefined, undefined, undefined)()).then(function (param) {
       return Promise.resolve(Router.push({
         TAG: /* Play */ 1,
         _0: gameId
diff --git a/output/src/client/ui/screens/Play.js b/output/src/client/ui/screens/Play.js
index dd83dc9..cc484a4 100644
--- a/output/src/client/ui/screens/Play.js
+++ b/output/src/client/ui/screens/Play.js
@@ -22,7 +22,7 @@ function useGame(id) {
   const setState = match[1];
   React.useEffect((function () {
     const abortController = new AbortController();
-    fetch(Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.get_game(undefined)), id), Fetch.RequestInit.make(/* Get */ 0, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, Caml_option.some(abortController.signal))(undefined)).then(function (prim) {
+    fetch(Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.get_game()), id), Fetch.RequestInit.make(/* Get */ 0, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, Caml_option.some(abortController.signal))()).then(function (prim) {
       return prim.json();
     }).then(function (data) {
       const game = Curry._1(Shared_client__Game.Api.Load.response_of_json, data);
@@ -57,7 +57,7 @@ function useMe(param) {
   const setState = match[1];
   React.useEffect((function () {
     const abortController = new AbortController();
-    fetch(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.me(undefined)), Fetch.RequestInit.make(/* Get */ 0, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, Caml_option.some(abortController.signal))(undefined)).then(function (prim) {
+    fetch(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.Api.me()), Fetch.RequestInit.make(/* Get */ 0, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, undefined, Caml_option.some(abortController.signal))()).then(function (prim) {
       return prim.json();
     }).then(function (data) {
       const me = Curry._1(Shared_client__Player.Api.WhoAmI.response_of_json, data);
@@ -85,7 +85,7 @@ function useMe(param) {
 function Play(Props) {
   let gameId = Props.gameId;
   const game = useGame(gameId);
-  const me = useMe(undefined);
+  const me = useMe();
   let exit = 0;
   if (typeof game === "string") {
     return null;
@@ -135,7 +135,7 @@ function Play(Props) {
     }
     
   }
-  const route = Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.join_game(undefined)), gameId);
+  const route = Curry._1(Shared_api_universal__Routes__Routes_Builder.sprintf(Shared_api_universal__Routes.join_game()), gameId);
   window.location.replace(route);
   return null;
 }
diff --git a/output/src/shared/api/universal/routes/Routes_Builder.js b/output/src/shared/api/universal/routes/Routes_Builder.js
index 39b1507..fc0f616 100644
--- a/output/src/shared/api/universal/routes/Routes_Builder.js
+++ b/output/src/shared/api/universal/routes/Routes_Builder.js
@@ -172,13 +172,13 @@ function union(t1, t2) {
       return r;
     }
     throw new Caml_js_exceptions.MelangeError("Assert_failure", {
-          MEL_EXN_ID: "Assert_failure",
-          _1: [
-            "src/shared/api/universal/routes/Routes_Builder.ml",
-            90,
-            27
-          ]
-        });
+        MEL_EXN_ID: "Assert_failure",
+        _1: [
+          "src/shared/api/universal/routes/Routes_Builder.ml",
+          90,
+          27
+        ]
+      });
   }), t1.children, t2.children);
   const match = t1.capture;
   const match$1 = t2.capture;
@@ -442,7 +442,7 @@ function string_of_route(r) {
 }
 
 function ksprintf(k, t) {
-  const k$1 = function (x) {
+  let k$1 = function (x) {
     return Curry._1(k, "/" + Stdlib__String.concat("/", x));
   };
   const aux = function (_k, _param) {
diff --git a/scrum-cards.opam b/scrum-cards.opam
index 40f55ca..8741651 100644
--- a/scrum-cards.opam
+++ b/scrum-cards.opam
@@ -19,9 +19,10 @@ depends: [
   "irmin-fs"
   "ppx_irmin"
   "lwt"
-  "melange" {= "5.0.1-53"}
+  "melange"
   "melange-fetch"
   "melange-json"
+  "melange-json-native"
   "melange-webapi"
   "reason"
   "reason-react"
diff --git a/src/client/images/Icons.re b/src/client/images/Icons.re
index 59f2752..c97f746 100644
--- a/src/client/images/Icons.re
+++ b/src/client/images/Icons.re
@@ -15,7 +15,7 @@ module ChevronDown = {
       />
     </svg>;
 
-  let prop = (~className=?, ()) => make({"className": className});
+  let prop = (~className=?, ()) => make({ "className": className });
 };
 
 module Checkmark = {
@@ -35,7 +35,7 @@ module Checkmark = {
       />
     </svg>;
 
-  let prop = (~className=?, ()) => make({"className": className});
+  let prop = (~className=?, ()) => make({ "className": className });
 };
 
 module ExclamationCircle = {
@@ -55,7 +55,7 @@ module ExclamationCircle = {
       />
     </svg>;
 
-  let prop = (~className=?, ()) => make({"className": className});
+  let prop = (~className=?, ()) => make({ "className": className });
 };
 
 module ExclamationTriangle = {
@@ -75,7 +75,7 @@ module ExclamationTriangle = {
       />
     </svg>;
 
-  let prop = (~className=?, ()) => make({"className": className});
+  let prop = (~className=?, ()) => make({ "className": className });
 };
 
 module Eye = {
@@ -100,7 +100,7 @@ module Eye = {
       />
     </svg>;
 
-  let prop = (~className=?, ()) => make({"className": className});
+  let prop = (~className=?, ()) => make({ "className": className });
 };
 
 module Info = {
@@ -120,5 +120,5 @@ module Info = {
       />
     </svg>;
 
-  let prop = (~className=?, ()) => make({"className": className});
+  let prop = (~className=?, ()) => make({ "className": className });
 };
diff --git a/src/client/ui/patterns/GameBoard/GameBoard.re b/src/client/ui/patterns/GameBoard/GameBoard.re
index 1c9676e..5bddd4e 100644
--- a/src/client/ui/patterns/GameBoard/GameBoard.re
+++ b/src/client/ui/patterns/GameBoard/GameBoard.re
@@ -100,7 +100,7 @@ let make =
       Bindings.Websocket.addEventListener(
         wsConnection,
         `message(
-          ({data}) => {
+          ({ data }) => {
             switch (
               data |> Js.Json.parseExn |> Shared.Api.Websocket.response_of_json
             ) {