diff --git a/Gemfile b/Gemfile
index 2c6fd29..13b1a06 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
 source "http://rubygems.org"
 
 gem "rscons"
+gem "rake"
+gem "json"
diff --git a/Gemfile.lock b/Gemfile.lock
index cadc72b..eed2c67 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,10 +1,14 @@
 GEM
   remote: http://rubygems.org/
   specs:
+    json (1.8.1)
+    rake (10.3.2)
     rscons (1.4.3)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  json
+  rake
   rscons