diff --git a/lib/spree/shipment_notice.rb b/lib/spree/shipment_notice.rb
index 2dbc0bd..570026d 100644
--- a/lib/spree/shipment_notice.rb
+++ b/lib/spree/shipment_notice.rb
@@ -17,7 +17,7 @@ def apply
     def locate
       if Spree::Config.shipstation_number == :order
         order = Spree::Order.find_by_number(@number)
-        @shipment = order.try(:shipment)
+        @shipment = order.try(:shipments).try(:first)
       else
         @shipment = Spree::Shipment.find_by_number(@number)
       end
@@ -27,9 +27,10 @@ def update
       @shipment.update_attribute(:tracking, @tracking)
 
       unless @shipment.shipped?
-        @shipment.reload.update_attribute(:state, 'shipped')
-        @shipment.inventory_units.each &:ship!
-        @shipment.touch :shipped_at
+        @shipment.reload.ship!
+        # @shipment.reload.update_attribute(:state, 'shipped')
+        # @shipment.inventory_units.each &:ship!
+        # @shipment.touch :shipped_at
       end
 
       true
diff --git a/spree_shipstation.gemspec b/spree_shipstation.gemspec
index 21ca95d..298b76c 100644
--- a/spree_shipstation.gemspec
+++ b/spree_shipstation.gemspec
@@ -16,7 +16,7 @@ Gem::Specification.new do |s|
   s.require_path = 'lib'
   s.requirements << 'none'
 
-  s.add_dependency 'spree_core', '~> 2.0'
+  s.add_dependency 'spree_core', '~> 2.4.0.beta'
 
   s.add_development_dependency 'capybara', '~> 1.1.2'
   s.add_development_dependency 'coffee-rails'