diff --git a/lib/ddtrace/contrib/rails/active_record.rb b/lib/ddtrace/contrib/rails/active_record.rb
index d2edba777c..4281d4ce58 100644
--- a/lib/ddtrace/contrib/rails/active_record.rb
+++ b/lib/ddtrace/contrib/rails/active_record.rb
@@ -8,6 +8,9 @@ module Rails
       # TODO[manu]: write docs
       module ActiveRecord
         def self.instrument
+          # ActiveRecord is instrumented only if it's available
+          return unless defined?(::ActiveRecord)
+
           # subscribe when the active record query has been processed
           ::ActiveSupport::Notifications.subscribe('sql.active_record') do |*args|
             sql(*args)
diff --git a/lib/ddtrace/contrib/rails/framework.rb b/lib/ddtrace/contrib/rails/framework.rb
index 2afe9178fc..fdd866b4ce 100644
--- a/lib/ddtrace/contrib/rails/framework.rb
+++ b/lib/ddtrace/contrib/rails/framework.rb
@@ -4,7 +4,7 @@
 require 'ddtrace/contrib/rails/core_extensions'
 require 'ddtrace/contrib/rails/action_controller'
 require 'ddtrace/contrib/rails/action_view'
-require 'ddtrace/contrib/rails/active_record' if defined?(::ActiveRecord)
+require 'ddtrace/contrib/rails/active_record'
 require 'ddtrace/contrib/rails/active_support'
 require 'ddtrace/contrib/rails/utils'
 
@@ -102,7 +102,7 @@ def self.auto_instrument
           # instrumenting Rails framework
           Datadog::Contrib::Rails::ActionController.instrument()
           Datadog::Contrib::Rails::ActionView.instrument()
-          Datadog::Contrib::Rails::ActiveRecord.instrument() if defined?(::ActiveRecord)
+          Datadog::Contrib::Rails::ActiveRecord.instrument()
           Datadog::Contrib::Rails::ActiveSupport.instrument()
 
           # by default, Rails 3 doesn't instrument the cache system