diff --git a/admin/app/components/solidus_admin/users/edit/component.html.erb b/admin/app/components/solidus_admin/users/edit/component.html.erb
index 98401c5d7df..6ab0b956feb 100644
--- a/admin/app/components/solidus_admin/users/edit/component.html.erb
+++ b/admin/app/components/solidus_admin/users/edit/component.html.erb
@@ -18,7 +18,7 @@
   <%= page_with_sidebar do %>
     <%= page_with_sidebar_main do %>
 
-      <%= render component('ui/panel').new(title: Spree.user_class.model_name.human) do %>
+      <%= render component('ui/panel').new(title: Spree.admin_user_class.model_name.human) do %>
         <%= solidus_form_for @user, url: solidus_admin.user_path(@user), html: { id: form_id, autocomplete: "off" } do |f| %>
           <div class="py-1.5">
             <%= f.text_field(:email) %>
diff --git a/admin/app/components/solidus_admin/users/index/component.rb b/admin/app/components/solidus_admin/users/index/component.rb
index 9a2041936e3..eb02dfa82a5 100644
--- a/admin/app/components/solidus_admin/users/index/component.rb
+++ b/admin/app/components/solidus_admin/users/index/component.rb
@@ -4,7 +4,7 @@ class SolidusAdmin::Users::Index::Component < SolidusAdmin::UsersAndRoles::Compo
   include SolidusAdmin::LastLoginHelper
 
   def model_class
-    Spree.user_class
+    Spree.admin_user_class
   end
 
   def search_key
diff --git a/admin/app/components/solidus_admin/users_and_roles/component.rb b/admin/app/components/solidus_admin/users_and_roles/component.rb
index 450aa352d0c..e55af008063 100644
--- a/admin/app/components/solidus_admin/users_and_roles/component.rb
+++ b/admin/app/components/solidus_admin/users_and_roles/component.rb
@@ -10,9 +10,9 @@ def title
   def tabs
     [
       {
-        text: Spree.user_class.model_name.human(count: 2),
+        text: Spree.admin_user_class.model_name.human(count: 2),
         href: solidus_admin.users_path,
-        current: model_class == Spree.user_class,
+        current: model_class == Spree.admin_user_class,
       },
       {
         text: Spree::Role.model_name.human(count: 2),
diff --git a/admin/app/controllers/solidus_admin/orders_controller.rb b/admin/app/controllers/solidus_admin/orders_controller.rb
index 0b2df6cb324..a113a64c605 100644
--- a/admin/app/controllers/solidus_admin/orders_controller.rb
+++ b/admin/app/controllers/solidus_admin/orders_controller.rb
@@ -95,7 +95,7 @@ def variants_for
     def customers_for
       load_order
 
-      @users = Spree.user_class
+      @users = Spree.admin_user_class
         .where.not(id: @order.user_id)
         .order(created_at: :desc, id: :desc)
         .ransack(params[:q])
diff --git a/admin/app/controllers/solidus_admin/store_credits_controller.rb b/admin/app/controllers/solidus_admin/store_credits_controller.rb
index 5d0ceb5b24b..036c60fe8ce 100644
--- a/admin/app/controllers/solidus_admin/store_credits_controller.rb
+++ b/admin/app/controllers/solidus_admin/store_credits_controller.rb
@@ -136,7 +136,7 @@ def set_store_credit
     end
 
     def set_user
-      @user = Spree.user_class.find(params[:user_id])
+      @user = Spree.admin_user_class.find(params[:user_id])
     end
 
     def set_store_credit_reasons
diff --git a/admin/app/controllers/solidus_admin/users_controller.rb b/admin/app/controllers/solidus_admin/users_controller.rb
index 04eaa09ac1e..893e75da159 100644
--- a/admin/app/controllers/solidus_admin/users_controller.rb
+++ b/admin/app/controllers/solidus_admin/users_controller.rb
@@ -15,7 +15,7 @@ class UsersController < SolidusAdmin::BaseController
 
     def index
       users = apply_search_to(
-        Spree.user_class.order(created_at: :desc, id: :desc),
+        Spree.admin_user_class.order(created_at: :desc, id: :desc),
         param: :q,
       )
 
@@ -73,9 +73,9 @@ def edit
     end
 
     def destroy
-      @users = Spree.user_class.where(id: params[:id])
+      @users = Spree.admin_user_class.where(id: params[:id])
 
-      Spree.user_class.transaction { @users.destroy_all }
+      Spree.admin_user_class.transaction { @users.destroy_all }
 
       flash[:notice] = t('.success')
       redirect_back_or_to users_path, status: :see_other
@@ -84,7 +84,7 @@ def destroy
     private
 
     def set_user
-      @user = Spree.user_class.find(params[:id])
+      @user = Spree.admin_user_class.find(params[:id])
     end
 
     def user_params
@@ -123,7 +123,7 @@ def set_items
     end
 
     def authorization_subject
-      Spree.user_class
+      Spree.admin_user_class
     end
   end
 end
diff --git a/admin/docs/index_pages.md b/admin/docs/index_pages.md
index d18c4b93592..7bfefa1d422 100644
--- a/admin/docs/index_pages.md
+++ b/admin/docs/index_pages.md
@@ -16,7 +16,7 @@ class SolidusAdmin::UsersController < SolidusAdmin::BaseController
   include SolidusAdmin::ControllerHelpers::Search
 
   def index
-    users = apply_search_to(Spree.user_class.order(id: :desc), param: :q)
+    users = apply_search_to(Spree.admin_user_class.order(id: :desc), param: :q)
     # ...
 ```
 
@@ -24,7 +24,7 @@ For pagination support, the index action should also call the `set_page_and_extr
 
 ```ruby
 def index
-  users = apply_search_to(Spree.user_class.order(id: :desc), param: :q)
+  users = apply_search_to(Spree.admin_user_class.order(id: :desc), param: :q)
   set_page_and_extract_portion_from(users)
   # ...
 ```
@@ -33,7 +33,7 @@ Finally, the index action should render the `index` component passing the `@page
 
 ```ruby
 def index
-  users = apply_search_to(Spree.user_class.order(id: :desc), param: :q)
+  users = apply_search_to(Spree.admin_user_class.order(id: :desc), param: :q)
   set_page_and_extract_portion_from(users)
   render component('users/index').new(page: @page)
 end
@@ -50,7 +50,7 @@ The index component requires only the `page` argument during initialization, all
 ```ruby
 class SolidusAdmin::Users::Index < Solidus::Admin::UI::Pages::Index
   def model_class
-    Spree.user_class
+    Spree.admin_user_class
   end
 end
 
@@ -92,7 +92,7 @@ end
 ```ruby
 # in the controller
 def delete
-  @users = Spree.user_class.where(id: params[:id])
+  @users = Spree.admin_user_class.where(id: params[:id])
   @users.destroy_all
   flash[:notice] = "Admin users deleted"
   redirect_to solidus_admin.users_path, status: :see_other
@@ -124,7 +124,7 @@ module SolidusAdmin
     search_scope(:all)
 
     def index
-      users = apply_search_to(Spree.user_class.order(id: :desc), param: :q)
+      users = apply_search_to(Spree.admin_user_class.order(id: :desc), param: :q)
       # ...
 ```
 
diff --git a/admin/spec/spec_helper.rb b/admin/spec/spec_helper.rb
index be6b774a657..6598f90ae35 100644
--- a/admin/spec/spec_helper.rb
+++ b/admin/spec/spec_helper.rb
@@ -53,6 +53,7 @@
 Capybara.disable_animation = true
 Capybara.default_max_wait_time = ENV['DEFAULT_MAX_WAIT_TIME'].to_f if ENV['DEFAULT_MAX_WAIT_TIME'].present?
 Capybara.enable_aria_label = true
+Capybara.server = :puma, { Silent: true } # A workaround for https://github.com/rspec/rspec-rails/issues/1897
 
 # DATABASE CLEANER
 require 'database_cleaner'
diff --git a/backend/app/controllers/spree/admin/orders/customer_details_controller.rb b/backend/app/controllers/spree/admin/orders/customer_details_controller.rb
index 5306a6dfe94..d794ffcc740 100644
--- a/backend/app/controllers/spree/admin/orders/customer_details_controller.rb
+++ b/backend/app/controllers/spree/admin/orders/customer_details_controller.rb
@@ -26,7 +26,7 @@ def update
           if @order.contents.update_cart(order_params)
 
             if should_associate_user?
-              requested_user = Spree.user_class.find(params[:user_id])
+              requested_user = Spree.admin_user_class.find(params[:user_id])
               @order.associate_user!(requested_user, @order.email.blank?)
             end
 
diff --git a/backend/app/controllers/spree/admin/orders_controller.rb b/backend/app/controllers/spree/admin/orders_controller.rb
index 3d989459af5..34b9fb3cb29 100644
--- a/backend/app/controllers/spree/admin/orders_controller.rb
+++ b/backend/app/controllers/spree/admin/orders_controller.rb
@@ -61,7 +61,7 @@ def index
       end
 
       def new
-        user = Spree.user_class.find_by(id: params[:user_id]) if params[:user_id]
+        user = Spree.admin_user_class.find_by(id: params[:user_id]) if params[:user_id]
         order_importer_params = order_params
         order_importer_params[:bill_address] = user&.bill_address
         order_importer_params[:ship_address] = user&.ship_address
diff --git a/backend/app/controllers/spree/admin/search_controller.rb b/backend/app/controllers/spree/admin/search_controller.rb
index 60fe94049e7..71729f2cd6c 100644
--- a/backend/app/controllers/spree/admin/search_controller.rb
+++ b/backend/app/controllers/spree/admin/search_controller.rb
@@ -11,9 +11,9 @@ class SearchController < Spree::Admin::BaseController
       def users
         if params[:ids]
           # split here may be String#split or Array#split, so we must flatten the results
-          @users = Spree.user_class.where(id: params[:ids].split(',').flatten)
+          @users = Spree.admin_user_class.where(id: params[:ids].split(',').flatten)
         else
-          @users = Spree.user_class.ransack({
+          @users = Spree.admin_user_class.ransack({
             m: 'or',
             email_start: params[:q],
             name_start: params[:q]
diff --git a/backend/app/controllers/spree/admin/store_credits_controller.rb b/backend/app/controllers/spree/admin/store_credits_controller.rb
index df377ee94aa..88b652193e9 100644
--- a/backend/app/controllers/spree/admin/store_credits_controller.rb
+++ b/backend/app/controllers/spree/admin/store_credits_controller.rb
@@ -3,7 +3,7 @@
 module Spree
   module Admin
     class StoreCreditsController < ResourceController
-      belongs_to 'spree/user', model_class: Spree.user_class
+      belongs_to 'spree/user', model_class: Spree.admin_user_class
       before_action :load_categories, only: [:new]
       before_action :load_reasons, only: [:edit_amount, :edit_validity]
       before_action :ensure_store_credit_reason, only: [:update_amount, :invalidate]
diff --git a/backend/app/controllers/spree/admin/users/api_key_controller.rb b/backend/app/controllers/spree/admin/users/api_key_controller.rb
index 894c2ae4705..4752cffa228 100644
--- a/backend/app/controllers/spree/admin/users/api_key_controller.rb
+++ b/backend/app/controllers/spree/admin/users/api_key_controller.rb
@@ -21,7 +21,7 @@ def destroy
         private
 
         def user
-          @user ||= Spree.user_class.find(params[:user_id])
+          @user ||= Spree.admin_user_class.find(params[:user_id])
         end
       end
     end
diff --git a/backend/app/controllers/spree/admin/users_controller.rb b/backend/app/controllers/spree/admin/users_controller.rb
index 177827780af..b53fff86779 100644
--- a/backend/app/controllers/spree/admin/users_controller.rb
+++ b/backend/app/controllers/spree/admin/users_controller.rb
@@ -21,7 +21,7 @@ def show
       end
 
       def create
-        @user = Spree.user_class.new(user_params)
+        @user = Spree.admin_user_class.new(user_params)
         if @user.save
           set_roles
           set_stock_locations
@@ -82,7 +82,7 @@ def items
       end
 
       def model_class
-        Spree.user_class
+        Spree.admin_user_class
       end
 
       private
diff --git a/backend/app/helpers/spree/admin/store_credit_events_helper.rb b/backend/app/helpers/spree/admin/store_credit_events_helper.rb
index 6b2188f67db..dad09289e9f 100644
--- a/backend/app/helpers/spree/admin/store_credit_events_helper.rb
+++ b/backend/app/helpers/spree/admin/store_credit_events_helper.rb
@@ -73,11 +73,11 @@ def store_credit_event_originator_link(store_credit_event)
   private
 
   # Cannot set the value for a user originator
-  # because Spree.user_class is not defined at that time.
+  # because Spree.admin_user_class is not defined at that time.
   # Spree::UserClassHandle does not work here either as
   # the assignment is evaluated before user_class is set
   def add_user_originator_link
-    originator_links[Spree.user_class.to_s] = {
+    originator_links[Spree.admin_user_class.to_s] = {
       new_tab: true,
       href_type: :user,
       translation_key: 'admin.store_credits.user_originator'
diff --git a/backend/app/views/spree/admin/store_credits/edit_amount.html.erb b/backend/app/views/spree/admin/store_credits/edit_amount.html.erb
index b3ce218b0fb..24b668e4c55 100644
--- a/backend/app/views/spree/admin/store_credits/edit_amount.html.erb
+++ b/backend/app/views/spree/admin/store_credits/edit_amount.html.erb
@@ -1,4 +1,4 @@
-<% admin_breadcrumb(link_to plural_resource_name(Spree::LegacyUser), spree.admin_users_path) %>
+<% admin_breadcrumb(link_to plural_resource_name(Spree.admin_user_class), spree.admin_users_path) %>
 <% admin_breadcrumb(link_to @user.email, edit_admin_user_url(@user)) %>
 <% admin_breadcrumb(link_to plural_resource_name(Spree::StoreCredit), spree.admin_user_store_credits_path(@user)) %>
 <% admin_breadcrumb(link_to Spree::StoreCredit.model_name.human, admin_user_store_credit_path(@user, @store_credit)) %>
diff --git a/backend/app/views/spree/admin/users/edit.html.erb b/backend/app/views/spree/admin/users/edit.html.erb
index a8b9c8aa76c..71e5d12b264 100644
--- a/backend/app/views/spree/admin/users/edit.html.erb
+++ b/backend/app/views/spree/admin/users/edit.html.erb
@@ -6,7 +6,7 @@
 <%= render partial: 'spree/admin/users/user_page_actions' %>
 
 <fieldset data-hook="admin_user_edit_general_settings">
-  <legend><%= Spree.user_class.model_name.human %></legend>
+  <legend><%= Spree.admin_user_class.model_name.human %></legend>
 
   <div data-hook="admin_user_edit_form_header">
     <%= render partial: 'spree/shared/error_messages', locals: { target: @user } %>
diff --git a/backend/app/views/spree/admin/users/index.html.erb b/backend/app/views/spree/admin/users/index.html.erb
index fd922000edf..5a73f2e8083 100644
--- a/backend/app/views/spree/admin/users/index.html.erb
+++ b/backend/app/views/spree/admin/users/index.html.erb
@@ -1,7 +1,7 @@
-<% admin_breadcrumb(plural_resource_name(Spree::LegacyUser)) %>
+<% admin_breadcrumb(plural_resource_name(Spree.admin_user_class)) %>
 
 <% content_for :page_actions do %>
-  <% if can?(:admin, Spree.user_class) && can?(:create, Spree.user_class) %>
+  <% if can?(:admin, Spree.admin_user_class) && can?(:create, Spree.admin_user_class) %>
     <li>
       <%= link_to t('spree.new_user'), new_admin_user_url, id: 'admin_new_user_link', class: 'btn btn-primary' %>
     </li>
@@ -24,7 +24,7 @@
         </div>
         <div class="col-xs-12 col-md-3">
           <div class="form-group">
-            <%= f.label :spree_roles_id_in, Spree.user_class.human_attribute_name(:spree_roles) %>
+            <%= f.label :spree_roles_id_in, Spree.admin_user_class.human_attribute_name(:spree_roles) %>
             <%= f.collection_select :spree_roles_id_in, @roles, :id, :name, {},
               multiple: true, class: 'select2 fullwidth' %>
           </div>
@@ -69,10 +69,10 @@
   </colgroup>
   <thead>
     <tr data-hook="admin_users_index_headers">
-      <th><%= sort_link @search, :email, Spree.user_class.human_attribute_name(:email), {title: 'users_email_title'} %></th>
-      <th><%= Spree.user_class.human_attribute_name(:spree_roles) %></th>
+      <th><%= sort_link @search, :email, Spree.admin_user_class.human_attribute_name(:email), {title: 'users_email_title'} %></th>
+      <th><%= Spree.admin_user_class.human_attribute_name(:spree_roles) %></th>
       <th class="align-center"><%= t('spree.num_orders') %></th>
-      <th class="align-center"><%= Spree.user_class.human_attribute_name(:lifetime_value) %></th>
+      <th class="align-center"><%= Spree.admin_user_class.human_attribute_name(:lifetime_value) %></th>
       <th class="align-center"><%= sort_link @search, :created_at, t('spree.member_since') %></th>
       <th data-hook="admin_users_index_header_actions" class="actions"></th>
     </tr>
diff --git a/backend/lib/spree/backend_configuration.rb b/backend/lib/spree/backend_configuration.rb
index 5621fb4641a..0307b7d6855 100644
--- a/backend/lib/spree/backend_configuration.rb
+++ b/backend/lib/spree/backend_configuration.rb
@@ -234,7 +234,7 @@ def menu_items
           label: :users,
           icon: admin_updated_navbar ? 'ri-user-line' : 'user',
           match_path: %r{/(users|store_credits)},
-          condition: -> { Spree.user_class && can?(:admin, Spree.user_class) },
+          condition: -> { Spree.admin_user_class && can?(:admin, Spree.admin_user_class) },
           url: :admin_users_path,
         ),
         MenuItem.new(
diff --git a/core/lib/generators/solidus/install/templates/config/initializers/spree.rb.tt b/core/lib/generators/solidus/install/templates/config/initializers/spree.rb.tt
index ea8a56aab94..cf9a6531452 100644
--- a/core/lib/generators/solidus/install/templates/config/initializers/spree.rb.tt
+++ b/core/lib/generators/solidus/install/templates/config/initializers/spree.rb.tt
@@ -83,6 +83,12 @@ end
   Spree.user_class = <%= options[:user_class].inspect %>
 <% end -%>
 
+# By default, admin users share the same class as storefront users.
+# Override this if you use a separate model for admin users.
+<% if options[:user_class].present? -%>
+  Spree.admin_user_class = <%= options[:user_class].inspect %>
+<% end -%>
+
 # Rules for avoiding to store the current path into session for redirects
 # When at least one rule is matched, the request path will not be stored
 # in session.
diff --git a/core/lib/spree/core.rb b/core/lib/spree/core.rb
index 0c7418d4f04..c806b93d2ed 100644
--- a/core/lib/spree/core.rb
+++ b/core/lib/spree/core.rb
@@ -30,6 +30,7 @@ module Spree
   autoload :Deprecation, 'spree/deprecation'
 
   mattr_accessor :user_class, default: 'Spree::LegacyUser'
+  mattr_accessor :admin_user_class, default: nil
 
   def self.user_class
     if @@user_class.is_a?(Class)
@@ -43,6 +44,22 @@ def self.user_class_name
     @@user_class
   end
 
+  # The class used for admin/backoffice users.
+  # Falls back to `Spree.user_class` for backwards compatibility.
+  def self.admin_user_class
+    return user_class if @@admin_user_class.nil?
+
+    if @@admin_user_class.is_a?(Class)
+      raise "Spree.admin_user_class MUST be a String or Symbol object, not a Class object."
+    elsif @@admin_user_class.is_a?(String) || @@admin_user_class.is_a?(Symbol)
+      @@admin_user_class.to_s.constantize
+    end
+  end
+
+  def self.admin_user_class_name
+    @@admin_user_class || @@user_class
+  end
+
   # Load the same version defaults for all available Solidus components
   #
   # @see Spree::Preferences::Configuration#load_defaults
diff --git a/core/lib/spree/testing_support/capybara_ext.rb b/core/lib/spree/testing_support/capybara_ext.rb
index 33dd0ffc694..494b01b9d53 100644
--- a/core/lib/spree/testing_support/capybara_ext.rb
+++ b/core/lib/spree/testing_support/capybara_ext.rb
@@ -4,7 +4,13 @@ module Spree
   module TestingSupport
     module CapybaraExt
       def click_icon(type)
-        find(".fa-#{type}").click
+        el = find(".fa-#{type}", visible: :all)
+        el.click
+      rescue Selenium::WebDriver::Error::ElementClickInterceptedError
+        # When a floating element (eg. tooltips/overlays) intercepts the click,
+        # scroll the target into view and dispatch a click via JS to keep tests stable.
+        page.execute_script('arguments[0].scrollIntoView({block: "center"});', el.native)
+        page.execute_script('arguments[0].click();', el.native)
       end
 
       def eventually_fill_in(field, options = {})
diff --git a/core/lib/spree/testing_support/dummy_app.rb b/core/lib/spree/testing_support/dummy_app.rb
index d0c9d7e69de..df91617df96 100644
--- a/core/lib/spree/testing_support/dummy_app.rb
+++ b/core/lib/spree/testing_support/dummy_app.rb
@@ -3,6 +3,14 @@
 ENV['RAILS_ENV'] = 'test'
 ENV['DISABLE_DATABASE_ENVIRONMENT_CHECK'] = '1'
 
+# Ensure sqlite3 v2 is supported when running with the default sqlite adapter.
+# The `fast_sqlite` gem relaxes ActiveRecord's sqlite3 version constraints.
+begin
+  require 'fast_sqlite'
+rescue LoadError
+  # Gem not available, skip.
+end
+
 require 'rails'
 require 'active_record/railtie'
 require 'action_controller/railtie'
@@ -106,7 +114,10 @@ class Application < ::Rails::Application
 
     # Set the preview path within the dummy app:
     if ActionMailer::Base.respond_to? :preview_paths # Rails 7.1+
-      config.action_mailer.preview_paths << File.expand_path('dummy_app/mailer_previews', __dir__)
+      # Some Rails versions return a frozen array here; assign a new array
+      # to avoid FrozenError when augmenting the paths.
+      existing = Array(config.action_mailer.preview_paths)
+      config.action_mailer.preview_paths = existing + [File.expand_path('dummy_app/mailer_previews', __dir__)]
     else
       config.action_mailer.preview_path = File.expand_path('dummy_app/mailer_previews', __dir__)
     end
diff --git a/docker-compose.yml b/docker-compose.yml
index 3e5b7009f97..203e0b8f46d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,4 +1,4 @@
-version: '3.7'
+version: "3.7"
 
 services:
   mysql:
@@ -18,12 +18,12 @@ services:
       - postgres:/var/lib/postgresql/data:cached
 
   app:
-    shm_size: '512mb'
+    shm_size: "512mb"
     build:
       context: .dockerdev
       dockerfile: Dockerfile
       args:
-        RUBY_VERSION: "3.1"
+        RUBY_VERSION: "3.4.6"
         PG_VERSION: 13
         NODE_VERSION: 20
         MYSQL_VERSION: "8.0"