diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 51e2d9d318e..dc118302d69 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -227,7 +227,7 @@ class CoursesController < ApplicationController
         if include_students
           proxy = section.enrollments
           if user_json_is_admin?
-            proxy = proxy.scoped(:include => { :user => :pseudonym })
+            proxy = proxy.scoped(:include => { :user => :pseudonyms })
           else
             proxy = proxy.scoped(:include => :user)
           end
@@ -256,7 +256,7 @@ class CoursesController < ApplicationController
     if authorized_action(@context, @current_user, :read_roster)
       proxy = @context.students
       if user_json_is_admin?
-        proxy = proxy.scoped(:include => :pseudonym)
+        proxy = proxy.scoped(:include => :pseudonyms)
       end
       render :json => proxy.map { |u| user_json(u, @current_user, session) }
     end
diff --git a/app/models/user.rb b/app/models/user.rb
index 1c1c86a90b2..6da63ab0d56 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -914,7 +914,11 @@ class User < ActiveRecord::Base
   def sis_pseudonym_for(context)
     root_account = context.root_account
     raise "could not resolve root account" unless root_account.is_a?(Account)
-    self.pseudonyms.active.find_by_account_id(root_account.id, :conditions => ["sis_user_id IS NOT NULL"])
+    if self.pseudonyms.loaded?
+      self.pseudonyms.detect { |p| p.active? && p.sis_user_id && p.account_id == root_account.id }
+    else
+      self.pseudonyms.active.find_by_account_id(root_account.id, :conditions => ["sis_user_id IS NOT NULL"])
+    end
   end
 
   set_policy do
diff --git a/lib/api/v1/user.rb b/lib/api/v1/user.rb
index f1de7503f9c..d0e6162e82c 100644
--- a/lib/api/v1/user.rb
+++ b/lib/api/v1/user.rb
@@ -26,14 +26,18 @@ module Api::V1::User
 
   def user_json(user, current_user, session, includes = [], context = @context)
     api_json(user, current_user, session, API_USER_JSON_OPTS).tap do |json|
-      if user_json_is_admin?(context, current_user) && pseudonym = user.pseudonym
-        # the sis fields on pseudonym are poorly named -- sis_user_id is
-        # the id in the SIS import data, where on every other table
-        # that's called sis_source_id.
-        json.merge! :sis_user_id => pseudonym.sis_user_id,
-            # TODO: don't send sis_login_id; it's garbage data
-                    :sis_login_id => pseudonym.sis_user_id ? pseudonym.unique_id : nil,
-                    :login_id => pseudonym.unique_id
+      if user_json_is_admin?(context, current_user)
+        if sis_pseudonym = user.sis_pseudonym_for(@domain_root_account)
+          # the sis fields on pseudonym are poorly named -- sis_user_id is
+          # the id in the SIS import data, where on every other table
+          # that's called sis_source_id.
+          json.merge! :sis_user_id => sis_pseudonym.sis_user_id,
+                      # TODO: don't send sis_login_id; it's garbage data
+                      :sis_login_id => sis_pseudonym.unique_id
+        end
+        if pseudonym = sis_pseudonym || user.find_pseudonym_for_account(@domain_root_account)
+          json[:login_id] = pseudonym.unique_id
+        end
       end
       if service_enabled?(:avatars) && includes.include?('avatar_url')
         json["avatar_url"] = avatar_image_url(user.id)
@@ -41,7 +45,7 @@ module Api::V1::User
     end
   end
 
-  # optimization hint, currently user only needs to pull pseudonym from the db
+  # optimization hint, currently user only needs to pull pseudonyms from the db
   # if a site admin is making the request or they can manage_students
   def user_json_is_admin?(context = @context, current_user = @current_user)
     @user_json_is_admin ||= {}
diff --git a/spec/apis/v1/enrollments_api_spec.rb b/spec/apis/v1/enrollments_api_spec.rb
index db1cd71e776..d815b8c78b9 100644
--- a/spec/apis/v1/enrollments_api_spec.rb
+++ b/spec/apis/v1/enrollments_api_spec.rb
@@ -276,6 +276,17 @@ describe EnrollmentsApiController, :type => :integration do
           res = res + @course.send("#{type}_enrollments").scoped(:include => :user)
         end
         json.should == enrollments.map do |e|
+          user_json = {
+                        'name' => e.user.name,
+                        'sortable_name' => e.user.sortable_name,
+                        'short_name' => e.user.short_name,
+                        'id' => e.user.id,
+                        'login_id' => e.user.pseudonym ? e.user.pseudonym.unique_id : nil
+                      }
+          user_json.merge!({
+              'sis_user_id' => e.user.pseudonym.sis_user_id,
+              'sis_login_id' => e.user.pseudonym.unique_id,
+            }) if e.user.pseudonym && e.user.pseudonym.sis_user_id
           {
             'root_account_id' => e.root_account_id,
             'limit_privileges_to_course_section' => e.limit_privileges_to_course_section,
@@ -285,15 +296,7 @@ describe EnrollmentsApiController, :type => :integration do
             'type' => e.type,
             'course_section_id' => e.course_section_id,
             'course_id' => e.course_id,
-            'user' => {
-              'name' => e.user.name,
-              'sortable_name' => e.user.sortable_name,
-              'short_name' => e.user.short_name,
-              'id' => e.user.id,
-              'sis_user_id' => e.user.pseudonym ? e.user.pseudonym.sis_user_id : nil,
-              'sis_login_id' => e.user.pseudonym && e.user.sis_user_id ? e.user.pseudonym.unique_id : nil,
-              'login_id' => e.user.pseudonym ? e.user.pseudonym.unique_id : nil
-            }
+            'user' => user_json
           }
         end
       end
diff --git a/spec/apis/v1/users_api_spec.rb b/spec/apis/v1/users_api_spec.rb
index 1d89c644ed2..39444bcd4c9 100644
--- a/spec/apis/v1/users_api_spec.rb
+++ b/spec/apis/v1/users_api_spec.rb
@@ -23,6 +23,9 @@ class TestUserApi
   attr_accessor :services_enabled, :context, :current_user
   def service_enabled?(service); @services_enabled.include? service; end
   def avatar_image_url(user_id); "avatar_image_url(#{user_id})"; end
+  def initialize
+    @domain_root_account = Account.default
+  end
 end
 
 describe Api::V1::User do
@@ -48,6 +51,54 @@ describe Api::V1::User do
       })
     end
 
+    it 'should use the correct SIS pseudonym' do
+      @user = User.create!(:name => 'User')
+      @account2 = Account.create!
+      @user.pseudonyms.create!(:unique_id => 'abc', :account => @account2) { |p| p.sis_user_id = 'abc' }
+      @user.pseudonyms.create!(:unique_id => 'xyz', :account => Account.default) { |p| p.sis_user_id = 'xyz' }
+      @test_api.user_json(@user, @admin, {}, [], Account.default).should == {
+          'name' => 'User',
+          'sortable_name' => 'User',
+          'sis_user_id' => 'xyz',
+          'id' => @user.id,
+          'short_name' => 'User',
+          'login_id' => 'xyz',
+          'sis_login_id' => 'xyz'
+        }
+    end
+
+    it 'should use the SIS pseudonym instead of another pseudonym' do
+      @user = User.create!(:name => 'User')
+      @account2 = Account.create!
+      @user.pseudonyms.create!(:unique_id => 'abc', :account => Account.default)
+      @user.pseudonyms.create!(:unique_id => 'xyz', :account => Account.default) { |p| p.sis_user_id = 'xyz' }
+      @test_api.user_json(@user, @admin, {}, [], Account.default).should == {
+          'name' => 'User',
+          'sortable_name' => 'User',
+          'sis_user_id' => 'xyz',
+          'id' => @user.id,
+          'short_name' => 'User',
+          'login_id' => 'xyz',
+          'sis_login_id' => 'xyz'
+        }
+    end
+
+    it 'should use the correct pseudonym' do
+      @user = User.create!(:name => 'User')
+      @account2 = Account.create!
+      @user.pseudonyms.create!(:unique_id => 'abc', :account => @account2)
+      @pseudonym = @user.pseudonyms.create!(:unique_id => 'xyz', :account => Account.default)
+      @user.stubs(:find_pseudonym_for_account).with(Account.default).returns(@pseudonym)
+      @test_api.user_json(@user, @admin, {}, [], Account.default).should == {
+          'name' => 'User',
+          'sortable_name' => 'User',
+          'id' => @user.id,
+          'short_name' => 'User',
+          'login_id' => 'xyz',
+        }
+    end
+
+
     def test_context(mock_context, context_to_pass)
       mock_context.expects(:account).returns(mock_context)
       mock_context.expects(:id).returns(42)
@@ -179,8 +230,6 @@ describe "Users API", :type => :integration do
       'sortable_name' => 'User',
       'short_name' => 'User',
       'primary_email' => 'nobody@example.com',
-      'sis_user_id' => nil,
-      'sis_login_id' => nil,
       'login_id' => 'nobody@example.com',
       'avatar_url' => "http://www.example.com/images/users/#{@admin.id}",
       'calendar' => { 'ics' => "http://www.example.com/feeds/calendars/user_#{@admin.uuid}.ics" },
@@ -250,15 +299,14 @@ describe "Users API", :type => :integration do
 
   describe "user account listing" do
     it "should return users for an account" do
-      @account = @user.account
+      @account = Account.default
       users = []
       [['Test User1', 'test@example.com'], ['Test User2', 'test2@example.com'], ['Test User3', 'test3@example.com']].each_with_index do |u, i|
-        users << User.create(:name => u[0])
-        users[i].pseudonyms.create(:unique_id => u[1], :password => '123456', :password_confirmation => '123456')
-        users[i].pseudonym.update_attribute(:sis_user_id, (i + 1) * 100)
-        users[i].pseudonym.update_attribute(:account_id, @account.id)
+        users << User.create!(:name => u[0])
+        users[i].pseudonyms.create!(:unique_id => u[1], :account => @account) { |p| p.sis_user_id = u[1] }
       end
       @account.all_users.scoped(:order => :sortable_name).each_with_index do |user, i|
+        next unless users.find { |u| u == user }
         json = api_call(:get, "/api/v1/accounts/#{@account.id}/users",
                { :controller => 'users', :action => 'index', :account_id => @account.id.to_param, :format => 'json' },
                { :per_page => 1, :page => i + 1 })
@@ -269,7 +317,7 @@ describe "Users API", :type => :integration do
           'id' => user.id,
           'short_name' => user.short_name,
           'login_id' => user.pseudonym.unique_id,
-          'sis_login_id' => user.pseudonym.sis_user_id ? user.pseudonym.unique_id : nil
+          'sis_login_id' => user.pseudonym.sis_user_id
         }]
       end
     end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 50080aa5254..39995b68c9e 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -1139,6 +1139,7 @@ describe User do
       u = User.create!
       pseudonyms = mock()
       u.stubs(:pseudonyms).returns(pseudonyms)
+      pseudonyms.stubs(:loaded?).returns(false)
       pseudonyms.stubs(:active).returns(pseudonyms)
       pseudonyms.expects(:find_by_account_id).with(@account.id, :conditions => ["sis_user_id IS NOT NULL"]).returns(42)
       u.sis_pseudonym_for(@course).should == 42
@@ -1151,6 +1152,7 @@ describe User do
       u = User.create!
       pseudonyms = mock()
       u.stubs(:pseudonyms).returns(pseudonyms)
+      pseudonyms.stubs(:loaded?).returns(false)
       pseudonyms.stubs(:active).returns(pseudonyms)
       pseudonyms.expects(:find_by_account_id).with(@account.id, :conditions => ["sis_user_id IS NOT NULL"]).returns(42)
       u.sis_pseudonym_for(@group).should == 42
@@ -1162,6 +1164,7 @@ describe User do
       u = User.create!
       pseudonyms = mock()
       u.stubs(:pseudonyms).returns(pseudonyms)
+      pseudonyms.stubs(:loaded?).returns(false)
       pseudonyms.stubs(:active).returns(pseudonyms)
       pseudonyms.expects(:find_by_account_id).with(@root_account.id, :conditions => ["sis_user_id IS NOT NULL"]).returns(42)
       u.sis_pseudonym_for(@account).should == 42
@@ -1172,6 +1175,7 @@ describe User do
       u = User.create!
       pseudonyms = mock()
       u.stubs(:pseudonyms).returns(pseudonyms)
+      pseudonyms.stubs(:loaded?).returns(false)
       pseudonyms.stubs(:active).returns(pseudonyms)
       pseudonyms.expects(:find_by_account_id).with(@account.id, :conditions => ["sis_user_id IS NOT NULL"]).returns(42)
       u.sis_pseudonym_for(@account).should == 42