diff --git a/Gemfile.lock b/Gemfile.lock
index 76d4dfb..b738948 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -137,7 +137,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-oauth2 (1.0.10)
       activesupport (>= 2.3)
       attr_required (>= 0.0.5)