diff --git a/packages/swagger-typescript-client-generator-runtime/lib/whatwg-fetch.js b/packages/swagger-typescript-client-generator-runtime/lib/whatwg-fetch.js
index bb7d73a..1d7bd5a 100644
--- a/packages/swagger-typescript-client-generator-runtime/lib/whatwg-fetch.js
+++ b/packages/swagger-typescript-client-generator-runtime/lib/whatwg-fetch.js
@@ -23,6 +23,9 @@ var WhatWgFetchRequestFactory = function (baseUrl, options) { return function (p
             return data;
         }, new FormData());
     }
+    else if (formData) {
+        fetchOptions.body = formData;
+    }
     var hasQuery = query && Object.keys(query).length > 0;
     var fullUrl = [
         baseUrl,
diff --git a/packages/swagger-typescript-client-generator-runtime/src/whatwg-fetch.ts b/packages/swagger-typescript-client-generator-runtime/src/whatwg-fetch.ts
index c597903..3432efe 100644
--- a/packages/swagger-typescript-client-generator-runtime/src/whatwg-fetch.ts
+++ b/packages/swagger-typescript-client-generator-runtime/src/whatwg-fetch.ts
@@ -11,50 +11,50 @@ export interface WhatWgFetchRequestFactoryOptions {
   fetch?: WhatWgFetchFunctionType
 }
 
-export const WhatWgFetchRequestFactory = (
-  baseUrl: string,
-  options: WhatWgFetchRequestFactoryOptions
-): RequestFactoryType => (
-  path,
-  query,
-  body,
-  formData,
-  headers,
-  method,
-  configuration: never
-) => {
-  const headersObject = new Headers(options.requestInit.headers || {})
-
-  new Headers(headers).forEach((value, key) => {
-    headersObject.set(key, String(value))
-  })
-
-  const fetchOptions: RequestInit = Object.assign({}, options.requestInit, {
-    method: method,
-    headers: headersObject
-  })
-
-  if (body && typeof body === "string") {
-    fetchOptions.body = body
-  } else if (body && typeof body === "object" && Object.keys(body).length > 0) {
-    fetchOptions.body = JSON.stringify(body)
-  } else if (formData && Object.keys(formData).length > 0) {
-    fetchOptions.body = Object.keys(formData).reduce((data, key) => {
-      data.append(key, formData[key])
-      return data
-    }, new FormData())
+export const WhatWgFetchRequestFactory =
+  (
+    baseUrl: string,
+    options: WhatWgFetchRequestFactoryOptions
+  ): RequestFactoryType =>
+  (path, query, body, formData, headers, method, configuration: never) => {
+    const headersObject = new Headers(options.requestInit.headers || {})
+
+    new Headers(headers).forEach((value, key) => {
+      headersObject.set(key, String(value))
+    })
+
+    const fetchOptions: RequestInit = Object.assign({}, options.requestInit, {
+      method: method,
+      headers: headersObject,
+    })
+
+    if (body && typeof body === "string") {
+      fetchOptions.body = body
+    } else if (
+      body &&
+      typeof body === "object" &&
+      Object.keys(body).length > 0
+    ) {
+      fetchOptions.body = JSON.stringify(body)
+    } else if (formData && Object.keys(formData).length > 0) {
+      fetchOptions.body = Object.keys(formData).reduce((data, key) => {
+        data.append(key, formData[key])
+        return data
+      }, new FormData())
+    } else if (formData) {
+      fetchOptions.body = formData
+    }
+
+    const hasQuery = query && Object.keys(query).length > 0
+    const fullUrl = [
+      baseUrl,
+      path,
+      hasQuery ? (path.includes("?") ? "&" : "?") : "",
+      hasQuery ? serialize(query) : "",
+    ].join("")
+
+    const callback: WhatWgFetchFunctionType =
+      typeof options.fetch === "function" ? options.fetch : fetch
+
+    return callback(fullUrl, fetchOptions)
   }
-
-  const hasQuery = query && Object.keys(query).length > 0
-  const fullUrl = [
-    baseUrl,
-    path,
-    hasQuery ? (path.includes("?") ? "&" : "?") : "",
-    hasQuery ? serialize(query) : ""
-  ].join("")
-
-  const callback: WhatWgFetchFunctionType =
-    typeof options.fetch === "function" ? options.fetch : fetch
-
-  return callback(fullUrl, fetchOptions)
-}