diff --git a/package.json b/package.json
index 3f72d07..34917da 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,6 @@
     "@testing-library/jest-dom": "^4.2.4",
     "@testing-library/react": "^9.3.2",
     "@testing-library/user-event": "^7.1.2",
-    "blob-to-buffer": "^1.2.8",
     "dexie": "^2.0.4",
     "interactjs": "^1.9.7",
     "js-binarypack": "^0.0.9",
diff --git a/src/helpers/Peer.js b/src/helpers/Peer.js
index b3aa6e0..04d8893 100644
--- a/src/helpers/Peer.js
+++ b/src/helpers/Peer.js
@@ -1,8 +1,9 @@
 import SimplePeer from "simple-peer";
 import BinaryPack from "js-binarypack";
-import toBuffer from "blob-to-buffer";
 import shortid from "shortid";
 
+import blobToBuffer from "./blobToBuffer";
+
 // Limit buffer size to 16kb to avoid issues with chrome packet size
 // http://viblast.com/blog/2015/2/5/webrtc-data-channel-message-size/
 const MAX_BUFFER_SIZE = 16000;
@@ -40,13 +41,9 @@ class Peer extends SimplePeer {
     });
   }
 
-  sendPackedData(packedData) {
-    toBuffer(packedData, (error, buffer) => {
-      if (error) {
-        throw error;
-      }
-      super.send(buffer);
-    });
+  async sendPackedData(packedData) {
+    const buffer = await blobToBuffer(packedData);
+    super.send(buffer);
   }
 
   send(data) {
diff --git a/src/helpers/blobToBuffer.js b/src/helpers/blobToBuffer.js
new file mode 100644
index 0000000..55eb6d7
--- /dev/null
+++ b/src/helpers/blobToBuffer.js
@@ -0,0 +1,13 @@
+async function blobToBuffer(blob) {
+  if (blob.arrayBuffer) {
+    const arrayBuffer = await blob.arrayBuffer();
+    const buffer = Buffer.from(arrayBuffer);
+    return buffer;
+  } else {
+    const arrayBuffer = await new Response(blob).arrayBuffer();
+    const buffer = Buffer.from(arrayBuffer);
+    return buffer;
+  }
+}
+
+export default blobToBuffer;
diff --git a/src/modals/SelectMapModal.js b/src/modals/SelectMapModal.js
index 0b2281a..951b764 100644
--- a/src/modals/SelectMapModal.js
+++ b/src/modals/SelectMapModal.js
@@ -11,6 +11,7 @@ import MapSettings from "../components/map/MapSettings";
 import AuthContext from "../contexts/AuthContext";
 
 import usePrevious from "../helpers/usePrevious";
+import blobToBuffer from "../helpers/blobToBuffer";
 
 import { maps as defaultMaps } from "../maps";
 
@@ -140,11 +141,14 @@ function SelectMapModal({
     }
     let image = new Image();
     setImageLoading(true);
+
+    // Copy file to avoid permissions issues
+    const copy = new Blob([file], { type: file.type });
     // Create and load the image temporarily to get its dimensions
-    const url = URL.createObjectURL(file);
+    const url = URL.createObjectURL(copy);
     image.onload = function () {
       handleMapAdd({
-        file,
+        file: copy,
         name,
         type: "file",
         gridX: fileGridX,
diff --git a/yarn.lock b/yarn.lock
index 2a3a068..437efce 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2711,11 +2711,6 @@ bindings@^1.5.0:
   dependencies:
     file-uri-to-path "1.0.0"
 
-blob-to-buffer@^1.2.8:
-  version "1.2.8"
-  resolved "https://registry.yarnpkg.com/blob-to-buffer/-/blob-to-buffer-1.2.8.tgz#78eeeb332f1280ed0ca6fb2b60693a8c6d36903a"
-  integrity sha512-re0AIxakF504MgeMtIyJkVcZ8T5aUxtp/QmTMlmjyb3P44E1BEv5x3LATBGApWAJATyXHtkXRD+gWTmeyYLiQA==
-
 blob@0.0.5:
   version "0.0.5"
   resolved "https://registry.yarnpkg.com/blob/-/blob-0.0.5.tgz#d680eeef25f8cd91ad533f5b01eed48e64caf683"