diff --git a/lib/book.js b/lib/book.js
index 2e0ab5811..b306c51ad 100644
--- a/lib/book.js
+++ b/lib/book.js
@@ -512,7 +512,7 @@ Book.prototype.parsePage = function(filename, options) {
     var interpolate = function(fn) {
         return Q(fn(page))
         .then(function(_page) {
-            page = _page;
+            page = _page || page;
         });
     };