diff --git a/plugins/elasticsearch/README.md b/plugins/elasticsearch/README.md
index 4e02a00..24cb9d5 100644
--- a/plugins/elasticsearch/README.md
+++ b/plugins/elasticsearch/README.md
@@ -10,7 +10,7 @@ Download: https://www.elastic.co/downloads/past-releases/elasticsearch-1-7-5
 INSTALL
 =======
 
-Install elasticsearch.
+Install elasticsearch and openjdk-7-jdk.
 
     $ cd plugins/elasticsearch
     $ rake install
diff --git a/plugins/elasticsearch/Rakefile b/plugins/elasticsearch/Rakefile
index bbea548..b904a66 100644
--- a/plugins/elasticsearch/Rakefile
+++ b/plugins/elasticsearch/Rakefile
@@ -13,5 +13,6 @@ end
 
 desc "install elasticsearch"
 task :install => :download do
+  sh 'sudo apt-get install openjdk-7-jdk'
   sh 'sudo dpkg -i /tmp/elasticsearch.deb || sudo apt-get install -f'
 end
--
libgit2 0.21.2