diff --git a/lib/pipedrive.rb b/lib/pipedrive.rb
index b872e92..9e5199f 100644
--- a/lib/pipedrive.rb
+++ b/lib/pipedrive.rb
@@ -2,6 +2,7 @@
 
 require 'logger'
 require 'active_support/core_ext/hash'
+require 'active_support/core_ext/array'
 require 'active_support/concern'
 require 'active_support/inflector'