diff --git a/config/application.rb b/config/application.rb
index 5c0557b..43600bb 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -34,6 +34,8 @@ module HenseiApi
     config.active_record.query_log_tags = [:application, :controller, :action, :job]
     config.active_record.cache_query_log_tags = true
 
+    config.active_support.to_time_preserves_timezone = :zone
+
     # API-only application configuration
     config.api_only = true
   end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 8b5160c..dd39c7a 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -1,4 +1,4 @@
-require "active_support/core_ext/integer/time"
+require 'active_support/core_ext/integer/time'
 
 # The test environment is used exclusively to run your application's
 # test suite. You never need to work with it otherwise. Remember that
@@ -9,21 +9,21 @@ Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
   # Turn false under Spring and add config.action_view.cache_template_loading = true.
-  config.cache_classes = true
+  config.cache_classes = false
 
   # Eager loading loads your whole application. When running a single test locally,
   # this probably isn't necessary. It's a good idea to do in a continuous integration
   # system, or in some way before deploying your code.
-  config.eager_load = ENV["CI"].present?
+  config.eager_load = ENV['CI'].present?
 
   # Configure public file server for tests with Cache-Control for performance.
   config.public_file_server.enabled = true
   config.public_file_server.headers = {
-    "Cache-Control" => "public, max-age=#{1.hour.to_i}"
+    'Cache-Control' => "public, max-age=#{1.hour.to_i}"
   }
 
   # Show full error reports and disable caching.
-  config.consider_all_requests_local       = true
+  config.consider_all_requests_local = true
   config.action_controller.perform_caching = false
   config.cache_store = :null_store
 
diff --git a/config/initializers/oj.rb b/config/initializers/oj.rb
new file mode 100644
index 0000000..5787a7b
--- /dev/null
+++ b/config/initializers/oj.rb
@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+# Explicitly configure Oj to mimic JSON.
+Oj::Rails.mimic_JSON