diff --git a/index.d.ts b/index.d.ts
index b272df8..e9f6e37 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,4 +1,5 @@
 /// <reference types="node" />
+import "isomorphic-fetch";
 export interface File {
     _id: string;
     type: "binary" | "text";
diff --git a/index.js b/index.js
index 8c1630a..5753232 100644
--- a/index.js
+++ b/index.js
@@ -1,7 +1,8 @@
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
 const rsa = require("node-rsa");
-const node_fetch_1 = require("node-fetch");
+require("isomorphic-fetch");
+const btb = require("blob-to-buffer");
 class SecureFile {
     constructor(server, username, private_key) {
         this.Server = server;
@@ -9,7 +10,7 @@ class SecureFile {
         this.PrivateKey = private_key;
     }
     async getCode() {
-        let code_res = await node_fetch_1.default(this.Server + "/code?username=" + this.Username);
+        let code_res = await fetch(this.Server + "/code?username=" + this.Username);
         //ToDo check status Codes
         let code = (await code_res.json()).code;
         let r = new rsa(this.PrivateKey, "pkcs1-pem");
@@ -27,7 +28,7 @@ class SecureFile {
             query_str += encodeURIComponent(key) + "=" + encodeURIComponent(query[key]);
             first = false;
         }
-        return await node_fetch_1.default(this.Server + endpoint + query_str, { method: method, body: body });
+        return await fetch(this.Server + endpoint + query_str, { method: method, body: body });
     }
     async test() {
         let res = await this.makeRequest("/test", "GET", {}, undefined);
@@ -65,7 +66,19 @@ class SecureFile {
             res = await this.makeRequest("/files/" + id, "GET", {}, undefined);
         }
         statusParser(res);
-        return res.buffer();
+        if (res.buffer) {
+            return res.buffer();
+        }
+        else {
+            return new Promise(async (resolve, reject) => {
+                btb(await res.blob(), (err, buffer) => {
+                    if (err)
+                        reject(err);
+                    else
+                        resolve(buffer);
+                });
+            });
+        }
     }
     async update(id, data, preview) {
         let put = {};
diff --git a/index.ts b/index.ts
index 50b2dfe..f9cd3e7 100644
--- a/index.ts
+++ b/index.ts
@@ -1,5 +1,7 @@
 import * as rsa from "node-rsa";
-import fetch, { Response } from "node-fetch";
+import "isomorphic-fetch";
+import * as btb from "blob-to-buffer"
+
 
 export interface File {
    _id: string;
@@ -84,7 +86,16 @@ export default class SecureFile {
          res = await this.makeRequest("/files/" + id, "GET", {}, undefined);
       }
       statusParser(res);
-      return res.buffer();
+      if ((<any>res).buffer) {
+         return (<any>res).buffer();
+      } else {
+         return new Promise<Buffer>(async (resolve, reject) => {
+            btb(await res.blob(), (err, buffer) => {
+               if (err) reject(err);
+               else resolve(buffer);
+            })
+         })
+      }
    }
 
    async update(id: string, data: Buffer, preview?: Buffer): Promise<File> {
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..235da2f
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,51 @@
+{
+   "name": "secure-file-wrapper",
+   "version": "1.0.2",
+   "lockfileVersion": 1,
+   "requires": true,
+   "dependencies": {
+      "encoding": {
+         "version": "0.1.12",
+         "resolved": "https://registry.npmjs.org/encoding/-/encoding-0.1.12.tgz",
+         "integrity": "sha1-U4tm8+5izRq1HsMjgp0flIDHS+s=",
+         "requires": {
+            "iconv-lite": "0.4.19"
+         }
+      },
+      "iconv-lite": {
+         "version": "0.4.19",
+         "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.19.tgz",
+         "integrity": "sha512-oTZqweIP51xaGPI4uPa56/Pri/480R+mo7SeU+YETByQNhDG55ycFyNLIgta9vXhILrxXDmF7ZGhqZIcuN0gJQ=="
+      },
+      "is-stream": {
+         "version": "1.1.0",
+         "resolved": "https://registry.npmjs.org/is-stream/-/is-stream-1.1.0.tgz",
+         "integrity": "sha1-EtSj3U5o4Lec6428hBc66A2RykQ="
+      },
+      "isomorphic-fetch": {
+         "version": "2.2.1",
+         "resolved": "https://registry.npmjs.org/isomorphic-fetch/-/isomorphic-fetch-2.2.1.tgz",
+         "integrity": "sha1-YRrhrPFPXoH3KVB0coGf6XM1WKk=",
+         "requires": {
+            "node-fetch": "1.7.3",
+            "whatwg-fetch": "2.0.3"
+         },
+         "dependencies": {
+            "node-fetch": {
+               "version": "1.7.3",
+               "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-1.7.3.tgz",
+               "integrity": "sha512-NhZ4CsKx7cYm2vSrBAr2PvFOe6sWDf0UYLRqA6svUYg7+/TSfVAu49jYC4BvQ4Sms9SZgdqGBgroqfDhJdTyKQ==",
+               "requires": {
+                  "encoding": "0.1.12",
+                  "is-stream": "1.1.0"
+               }
+            }
+         }
+      },
+      "whatwg-fetch": {
+         "version": "2.0.3",
+         "resolved": "https://registry.npmjs.org/whatwg-fetch/-/whatwg-fetch-2.0.3.tgz",
+         "integrity": "sha1-nITsLc9oGH/wC8ZOEnS0QhduHIQ="
+      }
+   }
+}
diff --git a/package.json b/package.json
index 30a7b55..769359e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
    "name": "secure-file-wrapper",
-   "version": "1.0.2",
+   "version": "1.0.4",
    "main": "index.js",
    "author": "Fabian Stamm <dev@fabianstamm.de>",
    "license": "MIT",
@@ -10,10 +10,13 @@
       "test": "nodeunit test.js"
    },
    "dependencies": {
-      "node-fetch": "^1.7.3",
+      "blob-to-buffer": "^1.2.7",
+      "isomorphic-fetch": "^2.2.1",
       "node-rsa": "^0.4.2"
    },
    "devDependencies": {
+      "@types/blob-to-buffer": "^1.2.0",
+      "@types/isomorphic-fetch": "^0.0.34",
       "@types/node": "^9.4.0",
       "@types/node-fetch": "^1.6.7",
       "@types/node-rsa": "^0.4.1",