diff --git a/.doc/Gemfile.lock b/.doc/Gemfile.lock
index e9256d483f..d03416cf4b 100644
--- a/.doc/Gemfile.lock
+++ b/.doc/Gemfile.lock
@@ -29,7 +29,7 @@ GEM
     parslet (1.3.0)
       blankslate (~> 2.0)
     posix-spawn (0.3.6)
-    rack (1.4.1)
+    rack (1.6.13)
     rack-protection (1.2.0)
       rack
     redcarpet (2.1.1)