diff --git a/web/viewer.js b/web/viewer.js
index 0f0b0b4d1..7d74ed8ac 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -434,6 +434,10 @@ var PDFViewerApplication = {
   },
 
   setTitle: function pdfViewSetTitle(title) {
+    if (this.isViewerEmbedded) {
+      // Embedded PDF viewers should not be changing their parent page's title.
+      return;
+    }
     document.title = title;
 //#if B2G
 //  document.getElementById('activityTitle').textContent = title;