diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..d8d37e7
Binary files /dev/null and b/.DS_Store differ
diff --git a/lib/chartmogul/metrics/activity.rb b/lib/chartmogul/metrics/activity.rb
index a5625f2..0abf586 100644
--- a/lib/chartmogul/metrics/activity.rb
+++ b/lib/chartmogul/metrics/activity.rb
@@ -12,6 +12,7 @@ class Activity < ChartMogul::Object
       readonly_attr :activity_mrr_movement
       readonly_attr :currency
       readonly_attr :currency_sign
+      readonly_attr :subscription_external_id
 
       def self.all(customer_uuid, options = {})
         ChartMogul::Metrics::Activities.all(customer_uuid, options)
diff --git a/lib/chartmogul/version.rb b/lib/chartmogul/version.rb
index 6d93dbb..4b5bdc6 100644
--- a/lib/chartmogul/version.rb
+++ b/lib/chartmogul/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module ChartMogul
-  VERSION = '1.6.7'
+  VERSION = '1.6.8'
 end
diff --git a/spec/.DS_Store b/spec/.DS_Store
new file mode 100644
index 0000000..8e601fa
Binary files /dev/null and b/spec/.DS_Store differ
diff --git a/spec/chartmogul/metrics/activities_spec.rb b/spec/chartmogul/metrics/activities_spec.rb
index 717824b..e7d9ee1 100644
--- a/spec/chartmogul/metrics/activities_spec.rb
+++ b/spec/chartmogul/metrics/activities_spec.rb
@@ -25,5 +25,6 @@
     expect(activity.activity_mrr_movement).not_to be_nil
     expect(activity.currency).not_to be_nil
     expect(activity.currency_sign).not_to be_nil
+    expect(activity.subscription_external_id).not_to be_nil
   end
 end