diff --git a/app/models/team.rb b/app/models/team.rb
index 77ee1325d52..5e266a6af81 100755
--- a/app/models/team.rb
+++ b/app/models/team.rb
@@ -261,7 +261,7 @@ def self.export(csv, parent_id, options, teamtype)
       if options[:team_name] == 'false'
         team_members = TeamsUser.where(team_id: team.id)
         team_members.each do |user|
-          user_export = user.respond_to?(:username) ? user.username : user.user
+          user_export = user.is_a?(User) ? user.username : user.user
           output.push(user_export)
         end
       end
diff --git a/app/models/user.rb b/app/models/user.rb
index e38248a9cb5..7465315cc10 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -20,7 +20,7 @@ class User < ApplicationRecord
   belongs_to :parent, class_name: 'User'
   belongs_to :role
   validates :username, presence: true
-  validates_uniqueness_of :username, :case_sensitive => true
+  validates_uniqueness_of :username
   validates :username, format: { without: /\s/ }
 
   validates :email, presence: { message: "can't be blank" }