diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40452ce..bf46c79 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,10 @@
 # main
 
 - Add bindings for `Response.json()`. https://github.com/zth/rescript-bun/pull/5
-  - Return JSON data with `Response.makeWithJson`
-  - Return any data type with `Response.makeWithJsonUnsafe`
+- Return JSON data with `Response.makeWithJson`
+- Return any data type with `Response.makeWithJsonUnsafe`
+- Upgrade to ReScript `>=11.1.0` and Core `>=1.3.0`.
+- Fix issue with bigint type.
 
 # 0.4.1
 
diff --git a/README.md b/README.md
index e86779c..86ef8a7 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ Use [Bun](https://bun.sh) with ReScript.
 
 **Template repo to get up and running quickly: https://github.com/zth/rescript-bun-starter**
 
-You need to be on at least a recent RC of ReScript v11. This is designed for uncurried mode so you should use that as well (`"uncurried": true` in your bsconfig/`rescript.json`).
+You need to be on ReScript v11 `>=11.1.0` and Core `>=1.3.0`. This is designed for uncurried mode so you should use that as well (`"uncurried": true` in your bsconfig/`rescript.json`).
 
 Install `rescript-bun` and `@rescript/core`:
 
diff --git a/package-lock.json b/package-lock.json
index ca81826..4e204d6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,27 +9,27 @@
       "version": "0.4.1",
       "license": "MIT",
       "devDependencies": {
-        "@rescript/core": "1.0.0",
-        "rescript": "11.1.0-rc.2"
+        "@rescript/core": "1.3.0",
+        "rescript": "11.1.1"
       },
       "peerDependencies": {
-        "@rescript/core": ">=1.0.0",
-        "rescript": ">=11.0.0 || ^11.1.0-rc.2"
+        "@rescript/core": ">=1.3.0",
+        "rescript": ">=11.1.0"
       }
     },
     "node_modules/@rescript/core": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/@rescript/core/-/core-1.0.0.tgz",
-      "integrity": "sha512-F5HURYYx8Kp6h1KBiri2nFwGKR16o9/XTCNl2TEWfCwqR+MTzf/lpuPuB6ajnaYytsU0kTUBIFI0DOoLgkDxSg==",
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/@rescript/core/-/core-1.3.0.tgz",
+      "integrity": "sha512-wNZOZ63sYcaIYZCmTZeIPCeLa3HCGgPbIOR8zjyNkoBYUlxNV8Nb2ZyqlXR5Mb9ttvv8fTV56JbKhyVEZEYo8g==",
       "dev": true,
       "peerDependencies": {
-        "rescript": ">=11.0.0 || ^11.1.0-rc.2"
+        "rescript": "^11.1.0-rc.7"
       }
     },
     "node_modules/rescript": {
-      "version": "11.1.0-rc.2",
-      "resolved": "https://registry.npmjs.org/rescript/-/rescript-11.1.0-rc.2.tgz",
-      "integrity": "sha512-kCUtmsODEUF1Eth5ppc+yIK79HLI7CwRs1R4iopDek4FC58IqHSLT3K1XHGB39YCWuOuV9WMly+wksHRJcSLcw==",
+      "version": "11.1.1",
+      "resolved": "https://registry.npmjs.org/rescript/-/rescript-11.1.1.tgz",
+      "integrity": "sha512-FMELeoiR1n3LzBdBt+k7U4l0vsz5Xh0HBSHf+0NhyhzZkMRLkEKEDNrcqZc6RIux9bxmxoO+zEa9qFM01VOXAw==",
       "dev": true,
       "hasInstallScript": true,
       "bin": {
diff --git a/package.json b/package.json
index e5a90c4..fe49d9e 100644
--- a/package.json
+++ b/package.json
@@ -20,11 +20,11 @@
   "author": "Gabriel Nordeborn",
   "license": "MIT",
   "devDependencies": {
-    "@rescript/core": "1.0.0",
-    "rescript": "11.1.0-rc.2"
+    "@rescript/core": "1.3.0",
+    "rescript": "11.1.1"
   },
   "peerDependencies": {
-    "rescript": ">=11.0.0 || ^11.1.0-rc.2",
-    "@rescript/core": ">=1.0.0"
+    "rescript": ">=11.1.0",
+    "@rescript/core": ">=1.3.0"
   }
 }
diff --git a/rescript.json b/rescript.json
index d60803d..9530186 100644
--- a/rescript.json
+++ b/rescript.json
@@ -14,7 +14,7 @@
     }
   ],
   "package-specs": {
-    "module": "es6",
+    "module": "esmodule",
     "in-source": true
   },
   "suffix": ".js",
diff --git a/src/Bun.res b/src/Bun.res
index 138cd38..cafa6ba 100644
--- a/src/Bun.res
+++ b/src/Bun.res
@@ -1189,11 +1189,11 @@ module Hash = {
 
   module Algorithms = {
     module WyHash = {
-      external hashString: (string, ~seed: BigInt.t=?) => BigInt.t = "Bun.hash.wyhash"
-      external hashArrayBufferView: (ArrayBufferView.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashString: (string, ~seed: bigint=?) => bigint = "Bun.hash.wyhash"
+      external hashArrayBufferView: (ArrayBufferView.t, ~seed: bigint=?) => bigint =
         "Bun.hash.wyhash"
-      external hashArrayBuffer: (ArrayBuffer.t, ~seed: BigInt.t=?) => BigInt.t = "Bun.hash.wyhash"
-      external hashSharedArrayBuffer: (SharedArrayBuffer.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashArrayBuffer: (ArrayBuffer.t, ~seed: bigint=?) => bigint = "Bun.hash.wyhash"
+      external hashSharedArrayBuffer: (SharedArrayBuffer.t, ~seed: bigint=?) => bigint =
         "Bun.hash.wyhash"
     }
 
@@ -1224,12 +1224,12 @@ module Hash = {
     }
 
     module CityHash64 = {
-      external hashString: (string, ~seed: BigInt.t=?) => BigInt.t = "Bun.hash.cityHash64"
-      external hashArrayBufferView: (ArrayBufferView.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashString: (string, ~seed: bigint=?) => bigint = "Bun.hash.cityHash64"
+      external hashArrayBufferView: (ArrayBufferView.t, ~seed: bigint=?) => bigint =
         "Bun.hash.cityHash64"
-      external hashArrayBuffer: (ArrayBuffer.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashArrayBuffer: (ArrayBuffer.t, ~seed: bigint=?) => bigint =
         "Bun.hash.cityHash64"
-      external hashSharedArrayBuffer: (SharedArrayBuffer.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashSharedArrayBuffer: (SharedArrayBuffer.t, ~seed: bigint=?) => bigint =
         "Bun.hash.cityHash64"
     }
 
@@ -1252,12 +1252,12 @@ module Hash = {
     }
 
     module Murmur64v2 = {
-      external hashString: (string, ~seed: BigInt.t=?) => BigInt.t = "Bun.hash.murmur64v2"
-      external hashArrayBufferView: (ArrayBufferView.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashString: (string, ~seed: bigint=?) => bigint = "Bun.hash.murmur64v2"
+      external hashArrayBufferView: (ArrayBufferView.t, ~seed: bigint=?) => bigint =
         "Bun.hash.murmur64v2"
-      external hashArrayBuffer: (ArrayBuffer.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashArrayBuffer: (ArrayBuffer.t, ~seed: bigint=?) => bigint =
         "Bun.hash.murmur64v2"
-      external hashSharedArrayBuffer: (SharedArrayBuffer.t, ~seed: BigInt.t=?) => BigInt.t =
+      external hashSharedArrayBuffer: (SharedArrayBuffer.t, ~seed: bigint=?) => bigint =
         "Bun.hash.murmur64v2"
     }
   }
diff --git a/src/Cluster.js b/src/Cluster.js
index 3f5b8a1..618be46 100644
--- a/src/Cluster.js
+++ b/src/Cluster.js
@@ -21,15 +21,6 @@ function classify(x) {
                       TAG: "TcpV4",
                       _0: x
                     };
-          case 0 :
-          case 1 :
-          case 2 :
-          case 3 :
-          case 5 :
-              return {
-                      TAG: "Unknown",
-                      _0: x
-                    };
           case 6 :
               return {
                       TAG: "TcpV6",
diff --git a/src/Process.res b/src/Process.res
index 55cfdca..6d696c8 100644
--- a/src/Process.res
+++ b/src/Process.res
@@ -145,7 +145,7 @@ external nextTickApply5: (t, @uncurry ('a, 'b, 'c, 'd, 'e) => unit, 'a, 'b, 'c,
   "nextTick"
 @send external hrtime: t => (int, int) = "hrtime"
 @send @scope("hrtime")
-external hrtimeBigInt: t => BigInt.t = "bigint"
+external hrtimeBigInt: t => bigint = "bigint"
 @get external stderr: t => Stream.Writable.t<Buffer.t> = "stderr"
 @get external stdin: t => Stream.Readable.t<Buffer.t> = "stdin"
 @get external stdout: t => Stream.Writable.t<Buffer.t> = "stdout"
diff --git a/test/Shell.test.js b/test/Shell.test.js
index f420a6e..ef4f7ae 100644
--- a/test/Shell.test.js
+++ b/test/Shell.test.js
@@ -7,7 +7,7 @@ Buntest.describe("shell", (function () {
         Buntest.test("basic commands work", (async function () {
                 var res = await $$Bun.$`echo "HELLO"`;
                 Buntest.expect(res.stdout.toString()).toBe("HELLO\n");
-              }), undefined);
+              }));
       }));
 
 export {