diff --git a/package.json b/package.json
index 534e7a7..bbbd3ee 100644
--- a/package.json
+++ b/package.json
@@ -29,7 +29,7 @@
   "scripts": {
     "test": "node tests/index.js",
     "build": "rewatch",
-    "format": "rescript format -all && prettier --write ./docs ./tests/index.js ./package.json",
+    "format": "rescript format -all && prettier --write ./tests/index.js ./package.json",
     "docs": "astro dev",
     "build:docs": "astro build"
   },
diff --git a/src/DOMAPI/Window.js b/src/DOMAPI/Window.js
index dbf8d92..977be07 100644
--- a/src/DOMAPI/Window.js
+++ b/src/DOMAPI/Window.js
@@ -1,7 +1,7 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
-import * as EventTarget$WebAPI from "../EventAPI/EventTarget.js";
+import * as EventTarget$WebApi from "../EventAPI/EventTarget.js";
 
-EventTarget$WebAPI.Impl({});
+EventTarget$WebApi.Impl({});
 
 /*  Not a pure module */
diff --git a/src/FetchAPI.res b/src/FetchAPI.res
index a3dca9b..0148de7 100644
--- a/src/FetchAPI.res
+++ b/src/FetchAPI.res
@@ -218,7 +218,9 @@ type urlSearchParams = {
   size: int,
 }
 
-type headersInit = any
+type headersInit
+
+type bodyInit
 
 type requestInfo = any
 
@@ -236,7 +238,7 @@ type requestInit = {
   /**
     A BodyInit object or null to set request's body.
     */
-  mutable body?: Null.t<bodyInit>,
+  mutable body?: bodyInit,
   /**
     A string whose value is a same-origin URL, "about:client", or the empty string, to set request's referrer.
     */
diff --git a/src/FetchAPI/BodyInit.js b/src/FetchAPI/BodyInit.js
new file mode 100644
index 0000000..d856702
--- /dev/null
+++ b/src/FetchAPI/BodyInit.js
@@ -0,0 +1,2 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+/* This output is empty. Its source's type definitions, externals and/or unused code got optimized away. */
diff --git a/src/FetchAPI/BodyInit.res b/src/FetchAPI/BodyInit.res
new file mode 100644
index 0000000..71e9a72
--- /dev/null
+++ b/src/FetchAPI/BodyInit.res
@@ -0,0 +1,47 @@
+open FileAPI
+open FetchAPI
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromString: string => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromArrayBuffer: ArrayBuffer.t => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromTypedArray: TypedArray.t<'t> => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromDataView: DataView.t => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromBlob: blob => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromFile: file => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromURLSearchParams: urlSearchParams => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromFormData: formData => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromReadableStream: readableStream<'t> => bodyInit = "%identity"
diff --git a/src/FetchAPI/HeadersInit.js b/src/FetchAPI/HeadersInit.js
new file mode 100644
index 0000000..d856702
--- /dev/null
+++ b/src/FetchAPI/HeadersInit.js
@@ -0,0 +1,2 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+/* This output is empty. Its source's type definitions, externals and/or unused code got optimized away. */
diff --git a/src/FetchAPI/HeadersInit.res b/src/FetchAPI/HeadersInit.res
new file mode 100644
index 0000000..2ca2f21
--- /dev/null
+++ b/src/FetchAPI/HeadersInit.res
@@ -0,0 +1,11 @@
+open FetchAPI
+
+/**
+ [Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_headers)
+ */
+external fromDict: dict<string> => headersInit = "%identity"
+
+/**
+ [Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_headers)
+ */
+external fromHeaders: headers => headersInit = "%identity"
diff --git a/src/Prelude.res b/src/Prelude.res
index 18579a0..fbc617f 100644
--- a/src/Prelude.res
+++ b/src/Prelude.res
@@ -5,8 +5,6 @@ external unsafeConversation: 'tinput => 'toutput = "%identity"
 
 type bufferSource = any
 
-type bodyInit = any
-
 type sharedArrayBuffer = any
 
 type float64Array = any
diff --git a/tests/Global__test.js b/tests/Global__test.js
index 9a955dc..42ad0d6 100644
--- a/tests/Global__test.js
+++ b/tests/Global__test.js
@@ -3,7 +3,16 @@
 
 let response = await fetch("https://rescript-lang.org/");
 
+let response2 = await fetch("https://rescript-lang.org/", {
+  headers: {
+    "Content-Type": "application/json",
+    Authorization: "Bearer token"
+  },
+  body: "secret=foo&response=bar"
+});
+
 export {
   response,
+  response2,
 }
 /* response Not a pure module */
diff --git a/tests/Global__test.res b/tests/Global__test.res
index ff4525e..01c2551 100644
--- a/tests/Global__test.res
+++ b/tests/Global__test.res
@@ -1,3 +1,16 @@
 open WebAPI.Global
 
 let response = await fetch("https://rescript-lang.org/")
+
+let response2 = await fetch(
+  "https://rescript-lang.org/",
+  ~init={
+    headers: HeadersInit.fromDict(
+      dict{
+        "Content-Type": "application/json",
+        "Authorization": "Bearer token",
+      },
+    ),
+    body: BodyInit.fromString(`secret=foo&response=bar`),
+  },
+)