diff --git a/web/pdf_attachment_viewer.js b/web/pdf_attachment_viewer.js
index dbfda4b3d..4b3e16f28 100644
--- a/web/pdf_attachment_viewer.js
+++ b/web/pdf_attachment_viewer.js
@@ -86,6 +86,38 @@ var PDFAttachmentViewer = (function PDFAttachmentViewerClosure() {
       this._renderedCapability.resolve();
     },
 
+    /**
+     * @private
+     */
+    _bindPdfLink:
+        function PDFAttachmentViewer_bindPdfLink(button, content, filename) {
+      var blobUrl;
+      button.onclick = function() {
+        if (!blobUrl) {
+          blobUrl = pdfjsLib.createObjectURL(
+            content, 'application/pdf', pdfjsLib.PDFJS.disableCreateObjectURL);
+        }
+        var viewerUrl;
+        if (typeof PDFJSDev === 'undefined' || PDFJSDev.test('GENERIC')) {
+          // The current URL is the viewer, let's use it and append the file.
+          viewerUrl = '?file=' + encodeURIComponent(blobUrl + '#' + filename);
+        } else if (PDFJSDev.test('CHROME')) {
+          // In the Chrome extension, the URL is rewritten using the history API
+          // in viewer.js, so an absolute URL must be generated.
+          // eslint-disable-next-line no-undef
+          viewerUrl = chrome.runtime.getURL('/content/web/viewer.html') +
+            '?file=' + encodeURIComponent(blobUrl + '#' + filename);
+        } else {
+          // Let Firefox's content handler catch the URL and display the PDF.
+          // In Firefox PDFJS.disableCreateObjectURL is always false, so
+          // blobUrl is always a blob:-URL and never a data:-URL.
+          viewerUrl = blobUrl + '?' + encodeURIComponent(filename);
+        }
+        window.open(viewerUrl);
+        return false;
+      };
+    },
+
     /**
      * @private
      */
@@ -124,11 +156,18 @@ var PDFAttachmentViewer = (function PDFAttachmentViewerClosure() {
       for (var i = 0; i < attachmentsCount; i++) {
         var item = attachments[names[i]];
         var filename = pdfjsLib.getFilenameFromUrl(item.filename);
+        filename = pdfjsLib.removeNullCharacters(filename);
+
         var div = document.createElement('div');
         div.className = 'attachmentsItem';
         var button = document.createElement('button');
-        this._bindLink(button, item.content, filename);
-        button.textContent = pdfjsLib.removeNullCharacters(filename);
+        button.textContent = filename;
+        if (/\.pdf$/i.test(filename)) {
+          this._bindPdfLink(button, item.content, filename);
+        } else {
+          this._bindLink(button, item.content, filename);
+        }
+
         div.appendChild(button);
         this.container.appendChild(div);
       }