diff --git a/doc/site/Gemfile.lock b/doc/site/Gemfile.lock
index 20da97b..a31a031 100644
--- a/doc/site/Gemfile.lock
+++ b/doc/site/Gemfile.lock
@@ -18,7 +18,8 @@ GEM
     ffi (1.0.11)
     fssm (0.2.9)
     haml (3.1.6)
-    kramdown (0.13.6)
+    kramdown (2.3.0)
+      rexml
     linecache (0.46)
       rbx-require-relative (> 0.0.4)
     nanoc (3.4.0)
@@ -30,6 +31,7 @@ GEM
     rack (1.4.1)
     rbx-require-relative (0.0.9)
     redcarpet (2.1.1)
+    rexml (3.2.4)
     ruby-debug (0.10.4)
       columnize (>= 0.1)
       ruby-debug-base (~> 0.10.4.0)