diff --git a/app/controllers/api/application_controller.rb b/app/controllers/api/application_controller.rb
index b8de05d..0bea5bc 100644
--- a/app/controllers/api/application_controller.rb
+++ b/app/controllers/api/application_controller.rb
@@ -1,11 +1,17 @@
 module API
   class ApplicationController < ::ApplicationController
+    rescue_from ActiveRecord::RecordNotFound, with: :not_found
+
     skip_before_filter :verify_authenticity_token
     skip_before_filter :authenticate!, only: :cor_preflight
 
     before_filter :cor_filter
     before_filter :json_filter!
 
+    def not_found
+      head :not_found
+    end
+
     def cor_filter
       headers['Access-Control-Allow-Origin'] = request.headers['Origin'] ?
         request.headers['Origin'] :
@@ -31,7 +37,9 @@ module API
     end
 
     def json_filter!
-      head :not_acceptable if request.format != :json
+      if request.format != :json
+        head :not_acceptable, content_type: 'application/json'
+      end
     end
   end
 end
diff --git a/config/routes.rb b/config/routes.rb
index dd5ae1a..70f0e84 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -8,6 +8,7 @@ Rails.application.routes.draw do
     resources :sessions, only: :create
     resources :sounds, only: :show
     resources :tracks, only: :index
+    match '*all', to: 'application#not_found', via: :all
   end
 
   resources :playlists
diff --git a/spec/integration/api/application_spec.rb b/spec/integration/api/application_spec.rb
index 8c7d26b..7f69dad 100644
--- a/spec/integration/api/application_spec.rb
+++ b/spec/integration/api/application_spec.rb
@@ -15,6 +15,21 @@ describe 'API application' do
     it 'responds with a 406 when request format is not JSON' do
       get api_ping_path, format: :xml
       expect(response.status).to be 406
+      expect(response.content_type).to eq :json
+      expect(response.body).to be_empty
+    end
+  end
+
+  describe 'not found' do
+    it 'responds with a 404 when route does not exist' do
+      get '/api/not_found', format: :json
+      expect(response.status).to be 404
+      expect(response.body).to be_empty
+    end
+
+    it 'responds with a 404 when a resource (AR) was not found' do
+      get api_playlist_path(id: 1), format: :json
+      expect(response.status).to be 404
       expect(response.body).to be_empty
     end
   end