diff --git a/.gitignore b/.gitignore
index ecc4f38e7..3edd9e228 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,4 +30,4 @@ node_modules/
 /public/generated-js/
 project/metals.sbt
 project/project/metals.sbt
-project/project/project/metals.sbt
\ No newline at end of file
+project/project/project/metals.sbt
diff --git a/app/views/createApplication.scala.html b/app/views/createApplication.scala.html
index a682c59f5..f8d2c2018 100644
--- a/app/views/createApplication.scala.html
+++ b/app/views/createApplication.scala.html
@@ -345,5 +345,4 @@ <h5 class="title--addline">
             }
         </div>
 }{
-        <script type="application/javascript" src="@routes.Assets.versioned("javascripts/application-attachment.js")"></script>
 }
diff --git a/app/views/showApplication.scala.html b/app/views/showApplication.scala.html
index fb352c50e..fb5335d4b 100644
--- a/app/views/showApplication.scala.html
+++ b/app/views/showApplication.scala.html
@@ -679,5 +679,4 @@ <h5 class="mdl-cell mdl-cell--12-col">Votre réponse :</h5>
     We use twemoji for emoji : https://github.com/twitter/twemoji
     -->
 }{
-    <script type="application/javascript" src="@routes.Assets.versioned("javascripts/application-attachment.js")"></script>
 }
diff --git a/public/javascripts/application-attachment.js b/public/javascripts/application-attachment.js
deleted file mode 100644
index 0e6e7321e..000000000
--- a/public/javascripts/application-attachment.js
+++ /dev/null
@@ -1,35 +0,0 @@
-ApplicationAttachment = {};
-
-window.document.addEventListener("DOMContentLoaded", function (event) {
-  "use strict";
-  var attachmentList = document.getElementById("attachment-list");
-  if (attachmentList != null) {
-    ApplicationAttachment.list = attachmentList;
-    ApplicationAttachment.fileInputCount = 1;
-    ApplicationAttachment.idSequence = 0; // In order to avoid id collisions
-    ApplicationAttachment.increaseOrDecreaseFileInputList = function (event) {
-      if (event.target.files.length > 0) {
-        // If a new file is added, add a new file input.
-        var li = document.createElement("li");
-        var input = document.createElement("input");
-        input.setAttribute("type", "file");
-        input.setAttribute("name", "file["+(ApplicationAttachment.idSequence++)+"]");
-        ApplicationAttachment.fileInputCount++;
-        input.addEventListener("change", ApplicationAttachment.increaseOrDecreaseFileInputList);
-        ApplicationAttachment.list.appendChild(li);
-        li.appendChild(input);
-      } else {
-        // If a previous file is unset for upload, remove the corresponding input file.
-        if (ApplicationAttachment.fileInputCount > 1) {
-          event.target.parentElement.parentElement.removeChild(event.target.parentElement);
-          ApplicationAttachment.fileInputCount--;
-        }
-      }
-    };
-    // For all file inputs, add a listener that adds a new file input to allow
-    // for more attachments to be made.
-    ApplicationAttachment.list.querySelectorAll("input").forEach(function (input) {
-      input.addEventListener("change", ApplicationAttachment.increaseOrDecreaseFileInputList);
-    });
-  }
-}, false);
diff --git a/typescript/src/application-attachment.ts b/typescript/src/application-attachment.ts
new file mode 100644
index 000000000..837e47a78
--- /dev/null
+++ b/typescript/src/application-attachment.ts
@@ -0,0 +1,55 @@
+interface ApplicationAttachment {
+  list: HTMLElement
+  fileInputCount: number
+  idSequence: number
+  increaseOrDecreaseFileInputList: (EventListener) => any
+}
+
+let attachment: any = {}
+
+
+const createAttachment = (list: HTMLElement, count: number, sequence: number): ApplicationAttachment => {
+  return {
+    list,
+    fileInputCount: count,
+    idSequence: sequence, // In order to avoid id collisions
+    increaseOrDecreaseFileInputList: event => {
+      if (event.target.files.length > 0) {
+        // If a new file is added, add a new file input.
+        const li: HTMLLIElement = document.createElement("li");
+        const input: HTMLInputElement = document.createElement("input");
+        input.setAttribute("type", "file");
+        input.setAttribute("name", "file[" + (attachment.idSequence++) + "]");
+        attachment.fileInputCount++;
+        input.addEventListener("change", attachment.increaseOrDecreaseFileInputList);
+        attachment.list.appendChild(li);
+        li.appendChild(input);
+      } else {
+        // If a previous file is unset for upload, remove the corresponding input file.
+        if (attachment.fileInputCount > 1) {
+          event.target.parentElement.parentElement.removeChild(event.target.parentElement);
+          attachment.fileInputCount--;
+        }
+      }
+    }
+  }
+}
+
+const main = (list: HTMLElement | null) => {
+  if (list != null) {
+    const attachment = createAttachment(list, 1, 0)
+    // For all file inputs, add a listener that adds a new file input to allow
+    // for more attachments to be made.
+    attachment.list.querySelectorAll("input").forEach(input => {
+      input.addEventListener("change", attachment.increaseOrDecreaseFileInputList);
+    });
+
+    return attachment;
+  }
+}
+
+window.document.addEventListener("DOMContentLoaded", _ => {
+  "use strict";
+  const attachmentList: HTMLElement | null = document.getElementById("attachment-list");
+  attachment = main(attachmentList)
+}, false);
diff --git a/typescript/src/index.ts b/typescript/src/index.ts
index 01da126f1..0cf9094e9 100644
--- a/typescript/src/index.ts
+++ b/typescript/src/index.ts
@@ -1,8 +1,11 @@
 // Polyfills
 // See https://github.com/ryanelian/ts-polyfill/tree/master/lib
 import 'ts-polyfill/lib/es2015-core';
+// This adds NodeList.forEach, etc.
+import 'core-js/web/dom-collections';
 
 // Our scripts
 import "./admin.ts"
 import "./mdl-extensions.ts"
-import "./validateAccount"
\ No newline at end of file
+import "./application-attachment"
+import "./validateAccount"