diff --git a/web/viewer.js b/web/viewer.js
index 4fc521459..bd65b37b0 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -1063,8 +1063,43 @@ var PDFView = {
     }
     var url = this.url.split('#')[0];
 //#if !(FIREFOX || MOZCENTRAL)
+
+    var a = document.createElement('a');
+
+    // If _parent == self, then opening an identical URL with different
+    // location hash will only cause a navigation, not a download.
+    if (window.top === window && !('download' in a) &&
+        url === window.location.href.split('#')[0]) {
+      url += url.indexOf('?') === -1 ? '?' : '&';
+    }
+
     url += '#pdfjs.action=download';
-    window.open(url, '_parent');
+    if (a.click) {
+      // Use a.click() if available. Otherwise, Chrome might show
+      // "Unsafe JavaScript attempt to initiate a navigation change
+      //  for frame with URL" and not open the PDF at all.
+      // Supported by (not mentioned = untested):
+      // - Firefox 6 - 19 (4- does not support a.click, 5 ignores a.click)
+      // - Chrome 19 - 26 (18- does not support a.click)
+      // - Opera 9 - 12.15
+      // - Internet Explorer 6 - 10
+      // - Safari 6 (5.1- does not support a.click)
+      a.href = url;
+      a.target = '_parent';
+      // Use a.download if available. This increases the likelihood that
+      // the file is downloaded instead of opened by another PDF plugin.
+      if ('download' in a) {
+        var filename = url.match(/([^\/?#=]+\.pdf)/i);
+        a.download = filename ? filename[1] : 'file.pdf';
+      }
+      // <a> must be in the document for IE and recent Firefox versions.
+      // (otherwise .click() is ignored)
+      (document.body || document.documentElement).appendChild(a);
+      a.click();
+      a.parentNode.removeChild(a);
+    } else {
+      window.open(url, '_parent');
+    }
 //#else
 //  // Document isn't ready just try to download with the url.
 //  if (!this.pdfDocument) {