diff --git a/django/conf/__init__.py b/django/conf/__init__.py
index 785302c6fd..c980ee0b28 100644
--- a/django/conf/__init__.py
+++ b/django/conf/__init__.py
@@ -7,6 +7,7 @@ a list of all possible variables.
 """
 
 import os
+import re
 import time     # Needed for Windows
 
 from django.conf import global_settings
@@ -91,8 +92,9 @@ class Settings(object):
                 appdir = os.path.dirname(__import__(app[:-2], {}, {}, ['']).__file__)
                 app_subdirs = os.listdir(appdir)
                 app_subdirs.sort()
+                name_pattern = re.compile(r'[a-zA-Z]\w*')
                 for d in app_subdirs:
-                    if d.isalnum() and d[0].isalpha() and os.path.isdir(os.path.join(appdir, d)):
+                    if name_pattern.match(d) and os.path.isdir(os.path.join(appdir, d)):
                         new_installed_apps.append('%s.%s' % (app[:-2], d))
             else:
                 new_installed_apps.append(app)
diff --git a/tests/regressiontests/app_loading/parent/__init__.py b/tests/regressiontests/app_loading/parent/__init__.py
index 51c842b5ba..e69de29bb2 100644
--- a/tests/regressiontests/app_loading/parent/__init__.py
+++ b/tests/regressiontests/app_loading/parent/__init__.py
@@ -1 +0,0 @@
-# not empty to make SVN happy
diff --git a/tests/regressiontests/app_loading/parent/app/__init__.py b/tests/regressiontests/app_loading/parent/app/__init__.py
index 51c842b5ba..e69de29bb2 100644
--- a/tests/regressiontests/app_loading/parent/app/__init__.py
+++ b/tests/regressiontests/app_loading/parent/app/__init__.py
@@ -1 +0,0 @@
-# not empty to make SVN happy
diff --git a/tests/regressiontests/app_loading/parent/app1/__init__.py b/tests/regressiontests/app_loading/parent/app1/__init__.py
index 51c842b5ba..e69de29bb2 100644
--- a/tests/regressiontests/app_loading/parent/app1/__init__.py
+++ b/tests/regressiontests/app_loading/parent/app1/__init__.py
@@ -1 +0,0 @@
-# not empty to make SVN happy
diff --git a/tests/regressiontests/app_loading/parent/app_2/__init__.py b/tests/regressiontests/app_loading/parent/app_2/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/regressiontests/app_loading/tests.py b/tests/regressiontests/app_loading/tests.py
index 444de10d79..bc958c0d88 100644
--- a/tests/regressiontests/app_loading/tests.py
+++ b/tests/regressiontests/app_loading/tests.py
@@ -14,7 +14,7 @@ Test the globbing of INSTALLED_APPS.
 >>> settings = Settings('test_settings')
 
 >>> settings.INSTALLED_APPS
-['parent.app', 'parent.app1']
+['parent.app', 'parent.app1', 'parent.app_2']
 
 >>> sys.path = old_sys_path