diff --git a/app/controllers/repositories_controller.rb b/app/controllers/repositories_controller.rb
index 9105aaef75..d7489a5e79 100644
--- a/app/controllers/repositories_controller.rb
+++ b/app/controllers/repositories_controller.rb
@@ -32,9 +32,9 @@ require 'SVG/Graph/BarHorizontal'
 require 'digest/sha1'
 require_dependency 'open_project/scm/adapters'
 
-class ChangesetNotFound < Exception
+class ChangesetNotFound < StandardError
 end
-class InvalidRevisionParam < Exception
+class InvalidRevisionParam < StandardError
 end
 
 class RepositoriesController < ApplicationController
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 3848f87ab8..46922a2638 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -1791,6 +1791,7 @@ en:
       code_403: "You are not authorized to access this resource."
       code_404: "The requested resource could not be found."
       code_409: "Couldn\'t update the resource because of conflicting modifications."
+      code_500: "An internal error has occured."
       invalid_content_type: "Expected CONTENT-TYPE to be '%{content_type}' but got '%{actual}'."
       invalid_format: "Invalid format for property '%{property}': Expected format like '%{expected_format}', but got '%{actual}'."
       invalid_json: "The request could not be parsed as JSON."
diff --git a/lib/api/errors/internal_error.rb b/lib/api/errors/internal_error.rb
new file mode 100644
index 0000000000..b32929cac5
--- /dev/null
+++ b/lib/api/errors/internal_error.rb
@@ -0,0 +1,40 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+module API
+  module Errors
+    class InternalError < ErrorBase
+      identifier 'urn:openproject-org:api:v3:errors:InternalServerError'
+
+      def initialize
+        super 500, I18n.t('api_v3.errors.code_500')
+      end
+    end
+  end
+end
diff --git a/lib/api/root.rb b/lib/api/root.rb
index 92a95ee286..31e8a315c9 100644
--- a/lib/api/root.rb
+++ b/lib/api/root.rb
@@ -176,6 +176,12 @@ module API
     error_response ::API::Errors::Unauthenticated, headers: auth_headers
     error_response ::API::Errors::ErrorBase, rescue_subclasses: true
 
+    # hide internal errors behind the same JSON response as all other errors
+    # only doing it in production to allow for easier debugging
+    if Rails.env.production?
+      error_response StandardError, ::API::Errors::InternalError.new, rescue_subclasses: true
+    end
+
     # run authentication before each request
     before do
       authenticate