diff --git a/manifests/init.pp b/manifests/init.pp
index 560edc5..661ffe9 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -16,7 +16,8 @@
 #
 class elasticsearch (
   $discover_nodes = ['localhost'],
-  $version = '0.20.5'
+  $version = '0.20.5',
+  $heap_size = '16g'
 ) {
   # install java runtime
   package { 'java7-runtime-headless':
@@ -96,7 +97,7 @@ class elasticsearch (
 
   file { '/etc/default/elasticsearch':
     ensure  => present,
-    source  => 'puppet:///modules/elasticsearch/elasticsearch.default',
+    content => template('elasticsearch/elasticsearch.default.erb'),
     replace => true,
     owner   => 'root',
     group   => 'root',
diff --git a/files/elasticsearch.default b/templates/elasticsearch.default.erb
similarity index 96%
rename from files/elasticsearch.default
rename to templates/elasticsearch.default.erb
index 1d1aac6..97ca450 100644
--- a/files/elasticsearch.default
+++ b/templates/elasticsearch.default.erb
@@ -3,7 +3,7 @@
 #ES_GROUP=elasticsearch
 
 # Heap Size (defaults to 256m min, 1g max)
-ES_HEAP_SIZE=16g
+ES_HEAP_SIZE=<%= heap_size %>
 
 # Heap new generation
 #ES_HEAP_NEWSIZE=