diff --git a/elasticsearch-extensions/lib/elasticsearch/extensions/test/cluster.rb b/elasticsearch-extensions/lib/elasticsearch/extensions/test/cluster.rb
index <HASH>..<HASH> 100644
--- a/elasticsearch-extensions/lib/elasticsearch/extensions/test/cluster.rb
+++ b/elasticsearch-extensions/lib/elasticsearch/extensions/test/cluster.rb
@@ -30,6 +30,7 @@ module Elasticsearch
       # @see Cluster#stop Cluster.stop
       #
       module Cluster
+        @@number_of_nodes = 0
 
         # Starts a cluster
         #
[EXT] Fixed, that the `@@number_of_nodes` variable is initialized on module load

This was preventing a use case like:

  time SERVER=y ruby -I lib:test test/integration/yaml_test_runner.rb