diff --git a/config/settings.yml b/config/settings.yml
index 17bdc10..a0aedb0 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -31,6 +31,6 @@ plugins:
     client: true
     type: group_list
     list_type: compact
-    default: ''
+    default: 'staff'
     allow_any: false
     refresh: true
diff --git a/jobs/scheduled/enqueue_reminders.rb b/jobs/scheduled/enqueue_reminders.rb
index 52d0aa4..ed364f9 100644
--- a/jobs/scheduled/enqueue_reminders.rb
+++ b/jobs/scheduled/enqueue_reminders.rb
@@ -16,7 +16,8 @@ module Jobs
     end
 
     def allowed_group_ids
-      Group.assign_allowed_groups.pluck(:id).join(',')
+      allowed_groups = SiteSetting.assign_allowed_on_groups.split('|')
+      Group.where(name: allowed_groups).pluck(:id).join(',')
     end
 
     def user_ids
diff --git a/lib/topic_assigner.rb b/lib/topic_assigner.rb
index 6372e46..563fbed 100644
--- a/lib/topic_assigner.rb
+++ b/lib/topic_assigner.rb
@@ -96,7 +96,7 @@ class ::TopicAssigner
       allowed_groups = SiteSetting.assign_allowed_on_groups.split('|')
 
       User.human_users
-        .assign_allowed
+        .joins(:groups).where(groups: { name: allowed_groups })
         .where('username_lower IN (?)', mentions.map(&:downcase))
         .first
     end
diff --git a/plugin.rb b/plugin.rb
index 92533d9..8b871a5 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -48,29 +48,11 @@ after_initialize do
 =end
   reviewable_api_enabled = defined?(Reviewable)
 
-  # TODO: Remove this once 2.4 becomes the new stable.
-  current_version = ActiveRecord::Migrator.current_version
-  min_version = 201_907_081_533_31
-  above_min_version = current_version >= min_version
-
-  # Dinamically sets the default value, supports older versions.
-  default_allowed_group_value = above_min_version ? Group::AUTO_GROUPS[:staff] : 'staff'
-  allowed_group_values = SiteSetting.assign_allowed_on_groups.split('|')
-  allowed_group_values << default_allowed_group_value if allowed_group_values.empty?
-  SiteSetting.assign_allowed_on_groups = allowed_group_values.join('|')
-
-  attribute = above_min_version ? 'id' : 'name'
-
-  add_class_method(:group, :assign_allowed_groups) do
-    allowed_groups = SiteSetting.assign_allowed_on_groups.split('|')
-    where("groups.#{attribute} IN (?)", allowed_groups)
-  end
-
   add_to_class(:user, :can_assign?) do
     @can_assign ||=
       begin
         allowed_groups = SiteSetting.assign_allowed_on_groups.split('|').compact
-        allowed_groups.present? && groups.where("groups.#{attribute} in (?)", allowed_groups).exists? ?
+        allowed_groups.present? && groups.where('name in (?)', allowed_groups).exists? ?
           :true : :false
       end
     @can_assign == :true
@@ -80,22 +62,21 @@ after_initialize do
 
   add_class_method(:user, :assign_allowed) do
     allowed_groups = SiteSetting.assign_allowed_on_groups.split('|')
-    where("users.id IN (
+    where('users.id IN (
       SELECT user_id FROM group_users
       INNER JOIN groups ON group_users.group_id = groups.id
-      WHERE groups.#{attribute} IN (?)
-    )", allowed_groups)
+      WHERE groups.name IN (?)
+    )', allowed_groups)
   end
 
   add_model_callback(Group, :before_update) do
-    if !above_min_version && name_changed?
+    if name_changed?
       SiteSetting.assign_allowed_on_groups = SiteSetting.assign_allowed_on_groups.gsub(name_was, name)
     end
   end
 
   add_model_callback(Group, :before_destroy) do
-    to_remove = above_min_version ? id : name
-    new_setting = SiteSetting.assign_allowed_on_groups.gsub(/#{to_remove}[|]?/, '')
+    new_setting = SiteSetting.assign_allowed_on_groups.gsub(/#{name}[|]?/, '')
     new_setting = new_setting.chomp('|') if new_setting.ends_with?('|')
     SiteSetting.assign_allowed_on_groups = new_setting
   end
diff --git a/spec/models/group_spec.rb b/spec/models/group_spec.rb
index 16241da..a269856 100644
--- a/spec/models/group_spec.rb
+++ b/spec/models/group_spec.rb
@@ -10,17 +10,19 @@ RSpec.describe Group do
       SiteSetting.assign_enabled = true
     end
 
-    let(:above_min_version) do
-      current_version = ActiveRecord::Migrator.current_version
-      min_version = 201_907_081_533_31
-      current_version >= min_version
+    it 'updates the site setting when the group name changes' do
+      SiteSetting.assign_allowed_on_groups = "#{group.name}|staff|moderators"
+      different_name = 'different_name'
+
+      group.update!(name: different_name)
+
+      expect(SiteSetting.assign_allowed_on_groups).to eq "#{different_name}|staff|moderators"
     end
 
-    let(:removed_group_setting) { above_min_version ? '3|4' : 'staff|moderators' }
-    let(:group_attribute) { above_min_version ? group.id : group.name }
+    let(:removed_group_setting) { 'staff|moderators' }
 
     it 'removes the group from the setting when the group gets destroyed' do
-      SiteSetting.assign_allowed_on_groups = "#{group_attribute}|#{removed_group_setting}"
+      SiteSetting.assign_allowed_on_groups = "#{group.name}|staff|moderators"
 
       group.destroy!
 
@@ -28,7 +30,7 @@ RSpec.describe Group do
     end
 
     it 'removes the group from the setting when this is the last one on the list' do
-      SiteSetting.assign_allowed_on_groups = "#{removed_group_setting}|#{group_attribute}"
+      SiteSetting.assign_allowed_on_groups = "staff|moderators|#{group.name}"
 
       group.destroy!
 
@@ -36,8 +38,7 @@ RSpec.describe Group do
     end
 
     it 'removes the group from the list when it is on the middle of the list' do
-      allowed_groups = above_min_version ? "3|#{group_attribute}|4" : "staff|#{group_attribute}|moderators"
-      SiteSetting.assign_allowed_on_groups = allowed_groups
+      SiteSetting.assign_allowed_on_groups = "staff|#{group.name}|moderators"
 
       group.destroy!
 
diff --git a/spec/requests/assign_controller_spec.rb b/spec/requests/assign_controller_spec.rb
index bd964db..d4fb776 100644
--- a/spec/requests/assign_controller_spec.rb
+++ b/spec/requests/assign_controller_spec.rb
@@ -11,12 +11,6 @@ RSpec.describe DiscourseAssign::AssignController do
   let(:post) { Fabricate(:post) }
   let(:user2) { Fabricate(:active_user) }
 
-  let(:above_min_version) do
-    current_version = ActiveRecord::Migrator.current_version
-    min_version = 201_907_081_533_31
-    current_version >= min_version
-  end
-
   describe 'only allow users from allowed groups' do
     before { sign_in(user2) }
 
@@ -37,13 +31,7 @@ RSpec.describe DiscourseAssign::AssignController do
         allowed_group = Group.find_by(name: 'everyone')
         user2.groups << allowed_group
         user2.groups << default_allowed_group
-        defaults = if above_min_version
-          "#{default_allowed_group.id}|#{allowed_group.id}"
-        else
-          "#{default_allowed_group.name}|#{allowed_group.name}"
-        end
-
-        SiteSetting.assign_allowed_on_groups = defaults
+        SiteSetting.assign_allowed_on_groups = 'staff|everyone'
         TopicAssigner.new(post.topic, user).assign(user2)
 
         get '/assign/suggestions.json'
@@ -55,7 +43,7 @@ RSpec.describe DiscourseAssign::AssignController do
       it 'does not include users from disallowed groups' do
         allowed_group = Group.find_by(name: 'everyone')
         user2.groups << allowed_group
-        SiteSetting.assign_allowed_on_groups = above_min_version ? default_allowed_group.id.to_s : default_allowed_group.name
+        SiteSetting.assign_allowed_on_groups = 'staff'
         TopicAssigner.new(post.topic, user).assign(user2)
 
         get '/assign/suggestions.json'