diff --git a/app/models/exchange.rb b/app/models/exchange.rb
index 243a311bcc..122586ba96 100644
--- a/app/models/exchange.rb
+++ b/app/models/exchange.rb
@@ -11,7 +11,7 @@ class Exchange < ActiveRecord::Base
   has_many :enterprise_fees, :through => :exchange_fees
 
   validates_presence_of :order_cycle, :sender, :receiver
-  validates_uniqueness_of :sender_id,   :scope => [:order_cycle_id, :receiver_id]
+  validates_uniqueness_of :sender_id, :scope => [:order_cycle_id, :receiver_id, :incoming]
 
   accepts_nested_attributes_for :variants
 
diff --git a/spec/models/exchange_spec.rb b/spec/models/exchange_spec.rb
index 403fceba87..9614a4d357 100644
--- a/spec/models/exchange_spec.rb
+++ b/spec/models/exchange_spec.rb
@@ -13,13 +13,17 @@ describe Exchange do
     end
   end
 
-  it "should not be valid when sender and receiver pair are not unique for its order cycle" do
+  it "should not be valid when (sender, receiver, direction) set are not unique for its order cycle" do
     e1 = create(:exchange)
 
     e2 = build(:exchange,
-               :order_cycle => e1.order_cycle, :sender => e1.sender, :receiver => e1.receiver)
+               :order_cycle => e1.order_cycle, :sender => e1.sender, :receiver => e1.receiver, :incoming => e1.incoming)
     e2.should_not be_valid
 
+    e2.incoming = !e2.incoming
+    e2.should be_valid
+    e2.incoming = !e2.incoming
+
     e2.receiver = create(:enterprise)
     e2.should be_valid