diff --git a/brooklyn-docs/Gemfile.lock b/brooklyn-docs/Gemfile.lock
index f48dc2b9af..28896a3f0d 100644
--- a/brooklyn-docs/Gemfile.lock
+++ b/brooklyn-docs/Gemfile.lock
@@ -1,7 +1,8 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.3.6)
+    addressable (2.8.0)
+      public_suffix (>= 2.0.2, < 5.0)
     blankslate (2.1.2.4)
     celluloid (0.16.0)
       timers (~> 4.0.0)
@@ -66,6 +67,7 @@ GEM
     parslet (1.5.0)
       blankslate (~> 2.0)
     posix-spawn (0.3.9)
+    public_suffix (3.1.1)
     pygments.rb (0.6.0)
       posix-spawn (~> 0.3.6)
       yajl-ruby (~> 1.1.0)