diff --git a/django/core/handlers/base.py b/django/core/handlers/base.py
index dac0adfb93c..79f6607214d 100644
--- a/django/core/handlers/base.py
+++ b/django/core/handlers/base.py
@@ -173,6 +173,9 @@ class BaseHandler(object):
             request_repr = "Request repr() unavailable"
         message = "%s\n\n%s" % (self._get_traceback(exc_info), request_repr)
         mail_admins(subject, message, fail_silently=True)
+        # If Http500 handler is not installed, re-raise last exception
+        if resolver.urlconf_module is None:
+            raise exc_info[1], None, exc_info[2]
         # Return an HttpResponse that displays a friendly error message.
         callback, param_dict = resolver.resolve500()
         return callback(request, **param_dict)
diff --git a/tests/regressiontests/urlpatterns_reverse/middleware.py b/tests/regressiontests/urlpatterns_reverse/middleware.py
index 7bb9aa924f1..cd3c0451598 100644
--- a/tests/regressiontests/urlpatterns_reverse/middleware.py
+++ b/tests/regressiontests/urlpatterns_reverse/middleware.py
@@ -5,3 +5,7 @@ import urlconf_inner
 class ChangeURLconfMiddleware(object):
     def process_request(self, request):
         request.urlconf = urlconf_inner.__name__
+
+class NullChangeURLconfMiddleware(object):
+    def process_request(self, request):
+        request.urlconf = None
diff --git a/tests/regressiontests/urlpatterns_reverse/tests.py b/tests/regressiontests/urlpatterns_reverse/tests.py
index d5f3ec95465..3fcc935da2f 100644
--- a/tests/regressiontests/urlpatterns_reverse/tests.py
+++ b/tests/regressiontests/urlpatterns_reverse/tests.py
@@ -17,6 +17,7 @@ ImproperlyConfigured: The included urlconf regressiontests.urlpatterns_reverse.n
 import unittest
 
 from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
 from django.core.urlresolvers import reverse, resolve, NoReverseMatch, Resolver404
 from django.http import HttpResponseRedirect, HttpResponsePermanentRedirect
 from django.shortcuts import redirect
@@ -282,16 +283,22 @@ class RequestURLconfTests(TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, 'outer:,inner:/second_test/')
 
+    def test_urlconf_overridden_with_null(self):
+        settings.MIDDLEWARE_CLASSES += (
+            '%s.NullChangeURLconfMiddleware' % middleware.__name__,
+        )
+        self.assertRaises(ImproperlyConfigured, self.client.get, '/test/me/')
+
 class ErrorHandlerResolutionTests(TestCase):
     """Tests for handler404 and handler500"""
-    
+
     def setUp(self):
         from django.core.urlresolvers import RegexURLResolver
         urlconf = 'regressiontests.urlpatterns_reverse.urls_error_handlers'
         urlconf_callables = 'regressiontests.urlpatterns_reverse.urls_error_handlers_callables'
         self.resolver = RegexURLResolver(r'^$', urlconf)
         self.callable_resolver = RegexURLResolver(r'^$', urlconf_callables)
-    
+
     def test_named_handlers(self):
         from views import empty_view
         handler = (empty_view, {})
@@ -303,3 +310,10 @@ class ErrorHandlerResolutionTests(TestCase):
         handler = (empty_view, {})
         self.assertEqual(self.callable_resolver.resolve404(), handler)
         self.assertEqual(self.callable_resolver.resolve500(), handler)
+
+class NoRootUrlConfTests(TestCase):
+    """Tests for handler404 and handler500 if urlconf is None"""
+    urls = None
+
+    def test_no_handler_exception(self):
+        self.assertRaises(ImproperlyConfigured, self.client.get, '/test/me/')