diff --git a/activerecord/lib/active_record/database_configurations/database_config.rb b/activerecord/lib/active_record/database_configurations/database_config.rb
index 14ca5eee31497a4b86e164e1f63d6bf5bc4ec17d..e52933a45671ddcfcd06df53590019736c4cf708 100644
--- a/activerecord/lib/active_record/database_configurations/database_config.rb
+++ b/activerecord/lib/active_record/database_configurations/database_config.rb
@@ -30,6 +30,10 @@ def database
         raise NotImplementedError
       end
 
+      def _database=(database)
+        raise NotImplementedError
+      end
+
       def adapter
         raise NotImplementedError
       end
diff --git a/activerecord/lib/active_record/database_configurations/hash_config.rb b/activerecord/lib/active_record/database_configurations/hash_config.rb
index 841a97edbecad6689edf9cf363cfa09b9d6233d5..25177c17eb85008bae408b43a4f950ef09172d91 100644
--- a/activerecord/lib/active_record/database_configurations/hash_config.rb
+++ b/activerecord/lib/active_record/database_configurations/hash_config.rb
@@ -61,6 +61,10 @@ def database
         configuration_hash[:database]
       end
 
+      def _database=(database) # :nodoc:
+        @config = configuration_hash.dup.merge(database: database).freeze
+      end
+
       def pool
         (configuration_hash[:pool] || 5).to_i
       end
diff --git a/activerecord/lib/active_record/test_databases.rb b/activerecord/lib/active_record/test_databases.rb
index 2c6cb691456219e3caedd239fb0467f0308a3369..ab4732bb80c6b712da1a588eff53d030897a8abc 100644
--- a/activerecord/lib/active_record/test_databases.rb
+++ b/activerecord/lib/active_record/test_databases.rb
@@ -12,23 +12,12 @@ def self.create_and_load_schema(i, env_name:)
       old, ENV["VERBOSE"] = ENV["VERBOSE"], "false"
 
       ActiveRecord::Base.configurations.configs_for(env_name: env_name).each do |db_config|
-        database = "#{db_config.database}-#{i}"
+        db_config._database = "#{db_config.database}-#{i}"
 
-        db_config_copy = ActiveRecord::DatabaseConfigurations::HashConfig.new(
-          env_name,
-          db_config.spec_name,
-          db_config.configuration_hash.merge(database: database)
-        )
-
-        # Reconstruct with the new configuration
-        ActiveRecord::Tasks::DatabaseTasks.reconstruct_from_schema(db_config_copy, ActiveRecord::Base.schema_format, nil)
-
-        # Replace the original configuration with our replacement
-        ActiveRecord::Base.configurations.configurations.delete(db_config)
-        ActiveRecord::Base.configurations.configurations.push(db_config_copy)
+        ActiveRecord::Tasks::DatabaseTasks.reconstruct_from_schema(db_config, ActiveRecord::Base.schema_format, nil)
       end
     ensure
-      ActiveRecord::Base.establish_connection(ActiveRecord::ConnectionHandling::DEFAULT_ENV.call.to_sym)
+      ActiveRecord::Base.establish_connection
       ENV["VERBOSE"] = old
     end
   end
diff --git a/activerecord/test/cases/test_databases_test.rb b/activerecord/test/cases/test_databases_test.rb
index 19f5cd025607bf33a880aeff40fdeb2f97b0c7f4..61910b202b52a823fd63dca2a97b945c98e8bea6 100644
--- a/activerecord/test/cases/test_databases_test.rb
+++ b/activerecord/test/cases/test_databases_test.rb
@@ -25,6 +25,7 @@ def test_databases_are_created
       ActiveRecord::Base.configurations = prev_configs
       ActiveRecord::Base.establish_connection(:arunit)
       ENV["RAILS_ENV"] = previous_env
+      FileUtils.rm_rf("db")
     end
 
     def test_create_databases_after_fork
@@ -45,12 +46,37 @@ def test_create_databases_after_fork
         ActiveSupport::Testing::Parallelization.after_fork_hooks.each { |cb| cb.call(idx) }
       end
 
-      # Updates the databse configuration
+      # Updates the database configuration
       assert_equal expected_database, ActiveRecord::Base.configurations.configs_for(env_name: "arunit", spec_name: "primary").database
     ensure
       ActiveRecord::Base.configurations = prev_configs
       ActiveRecord::Base.establish_connection(:arunit)
       ENV["RAILS_ENV"] = previous_env
+      FileUtils.rm_rf("db")
+    end
+
+    def test_order_of_configurations_isnt_changed_by_test_databases
+      previous_env, ENV["RAILS_ENV"] = ENV["RAILS_ENV"], "arunit"
+      prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, {
+        "arunit" => {
+          "primary" => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" },
+          "replica" => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" }
+        }
+      }
+
+      idx = 42
+      base_configs_order = ActiveRecord::Base.configurations.configs_for(env_name: "arunit").map(&:spec_name)
+
+      ActiveRecord::Tasks::DatabaseTasks.stub(:reconstruct_from_schema, ->(db_config, _, _) {
+        assert_equal base_configs_order, ActiveRecord::Base.configurations.configs_for(env_name: "arunit").map(&:spec_name)
+      }) do
+        ActiveSupport::Testing::Parallelization.after_fork_hooks.each { |cb| cb.call(idx) }
+      end
+    ensure
+      ActiveRecord::Base.configurations = prev_configs
+      ActiveRecord::Base.establish_connection(:arunit)
+      ENV["RAILS_ENV"] = previous_env
+      FileUtils.rm_rf("db")
     end
   end
 end