diff --git a/.doc/Gemfile.lock b/.doc/Gemfile.lock
index e9256d483f..d36f57e88a 100644
--- a/.doc/Gemfile.lock
+++ b/.doc/Gemfile.lock
@@ -32,7 +32,7 @@ GEM
     rack (1.4.1)
     rack-protection (1.2.0)
       rack
-    redcarpet (2.1.1)
+    redcarpet (3.5.1)
     rocco (0.8.2)
       mustache
       redcarpet