diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index b3455e04c29fc97e03a52032ee7c694e0ecc54c0..705824502eb971a698e9df4a050751cda66c61c9 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -45,6 +45,10 @@ class ApplicationController < ActionController::Base
     redirect_to request.referer.present? ? :back : default, options
   end
 
+  def not_found
+    render_404
+  end
+
   protected
 
   # This filter handles both private tokens and personal access tokens
diff --git a/config/routes.rb b/config/routes.rb
index 83c3a42c19f4e4ded4f2a7a8578d24812c46da3e..659ea51bc75b67e6dbcd842b53312483e1574112 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -88,4 +88,6 @@ Rails.application.routes.draw do
   get ':username.keys' => 'profiles/keys#get_keys', constraints: { username: /.*/ }
 
   root to: "root#index"
+
+  get '*unmatched_route', to: 'application#not_found'
 end
diff --git a/spec/requests/git_http_spec.rb b/spec/requests/git_http_spec.rb
index 5a1ed7d4a25f6b88f986554c399308b202a299d1..27f0fd22ae62a3f0716e28628149d83db5936be1 100644
--- a/spec/requests/git_http_spec.rb
+++ b/spec/requests/git_http_spec.rb
@@ -412,9 +412,10 @@ describe 'Git HTTP requests', lib: true do
 
         context "when the params are anything else" do
           let(:params) { { service: 'git-implode-pack' } }
+          before { get path, params }
 
-          it "fails to find a route" do
-            expect { get(path, params) }.to raise_error(ActionController::RoutingError)
+          it "redirects to the sign-in page" do
+            expect(response).to redirect_to(new_user_session_path)
           end
         end
       end