diff --git a/app/models/add_member.rb b/app/models/add_member.rb
index 4bb7635..518817e 100644
--- a/app/models/add_member.rb
+++ b/app/models/add_member.rb
@@ -12,7 +12,7 @@ class AddMember < Task
 
   def perform
     self.roles ||= [Profile::Roles.member(organization.environment.id).id]
-    target.affiliate(requestor, self.roles.map{|i| Role.find(i)})
+    target.affiliate(requestor, self.roles.select{|r| !r.to_i.zero? }.map{|i| Role.find(i)})
   end
 
   def description
diff --git a/test/unit/add_member_test.rb b/test/unit/add_member_test.rb
index c676345..6e5f482 100644
--- a/test/unit/add_member_test.rb
+++ b/test/unit/add_member_test.rb
@@ -95,4 +95,17 @@ class AddMemberTest < ActiveSupport::TestCase
     end
   end
 
+  should 'ignore roles with id zero' do
+    p = create_user('testuser1').person
+    c = Community.create!(:name => 'community_test')
+
+    role = Profile::Roles.member(c.environment.id)
+    TaskMailer.stubs(:deliver_target_notification)
+    task = AddMember.create!(:roles => ["0", role.id, nil], :person => p, :organization => c)
+    task.finish
+
+    current_roles = p.find_roles(c).map(&:role)
+    assert_includes current_roles, role
+  end
+
 end
--
libgit2 0.21.2