diff --git a/src/core.js b/src/core.js
index 2bc4c50aa..5685cdf31 100644
--- a/src/core.js
+++ b/src/core.js
@@ -7,7 +7,7 @@ var globalScope = (typeof window === 'undefined') ? this : window;
 
 var ERRORS = 0, WARNINGS = 1, TODOS = 5;
 var verbosity = WARNINGS;
-var useWorker = false;
+var useWorker = true;
 
 // The global PDFJS object exposes the API
 // In production, it will be declared outside a global wrapper
diff --git a/web/viewer.html b/web/viewer.html
index 60eab8eab..3883804f0 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -26,7 +26,7 @@
         <script type="text/javascript" src="../src/stream.js"></script>  <!-- PDFJSSCRIPT_REMOVE -->
         <script type="text/javascript" src="../src/worker.js"></script>  <!-- PDFJSSCRIPT_REMOVE -->
 
-        <script type="text/javascript">PDFJS.workerSrc = '../../src/worker_loader.js';</script> <!-- PDFJSSCRIPT_REMOVE -->
+        <script type="text/javascript">PDFJS.workerSrc = '../src/worker_loader.js';</script> <!-- PDFJSSCRIPT_REMOVE -->
 
         <script type="text/javascript" src="viewer.js"></script>
   </head>