diff --git a/Gemfile.lock b/Gemfile.lock
index 88f8856..3938895 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -39,7 +39,8 @@ GEM
       jekyll (>= 3.7, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    kramdown (1.17.0)
+    kramdown (2.3.1)
+      rexml
     liquid (4.0.3)
     listen (3.2.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
@@ -51,6 +52,7 @@ GEM
     rb-fsevent (0.10.3)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
+    rexml (3.2.5)
     rouge (3.3.0)
     safe_yaml (1.0.5)
     sass (3.7.4)