diff --git a/django/conf/__init__.py b/django/conf/__init__.py
index 531eed8658..5e4b412f32 100644
--- a/django/conf/__init__.py
+++ b/django/conf/__init__.py
@@ -103,6 +103,9 @@ class Settings(BaseSettings):
                 setting_value = getattr(mod, setting)
                 if setting in tuple_settings and \
                         isinstance(setting_value, basestring):
+                    warnings.warn("The %s setting must be a tuple. Please fix your "
+                                  "settings, as auto-correction is now deprecated." % setting,
+                        PendingDeprecationWarning)
                     setting_value = (setting_value,) # In case the user forgot the comma.
                 setattr(self, setting, setting_value)
 
diff --git a/docs/internals/deprecation.txt b/docs/internals/deprecation.txt
index 342ef5266a..f338adac33 100644
--- a/docs/internals/deprecation.txt
+++ b/docs/internals/deprecation.txt
@@ -276,6 +276,10 @@ these changes.
 * The function ``django.utils.itercompat.product`` will be removed. The Python
   builtin version should be used instead.
 
+* Auto-correction of INSTALLED_APPS and TEMPLATE_DIRS settings when they are
+  specified as a plain string instead of a tuple will be removed and raise an
+  exception.
+
 2.0
 ---