diff --git a/CHANGES b/CHANGES
index 912c6aaf..8699718c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -21,6 +21,9 @@ Version 0.10.2
 (bugfix release, release date to be announced)
 
 - Fixed broken `test_appcontext_signals()` test case.
+- Raise an :exc:`AttributeError` in :func:`flask.helpers.find_package` with a
+  useful message explaining why it is raised when a PEP 302 import hook is used
+  without an `is_package()` method.
 
 Version 0.10.1
 --------------
diff --git a/docs/api.rst b/docs/api.rst
index 75295b1e..5faccc30 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -350,7 +350,7 @@ JSON Support
 Flask uses ``simplejson`` for the JSON implementation.  Since simplejson
 is provided both by the standard library as well as extension Flask will
 try simplejson first and then fall back to the stdlib json module.  On top
-of that it will delegate access to the current application's JSOn encoders
+of that it will delegate access to the current application's JSON encoders
 and decoders for easier customization.
 
 So for starters instead of doing::
diff --git a/docs/deploying/fastcgi.rst b/docs/deploying/fastcgi.rst
index 1ac1f505..430a9748 100644
--- a/docs/deploying/fastcgi.rst
+++ b/docs/deploying/fastcgi.rst
@@ -149,6 +149,7 @@ A basic FastCGI configuration for lighttpd looks like that::
     url.rewrite-once = (
         "^(/static($|/.*))$" => "$1",
         "^(/.*)$" => "/yourapplication.fcgi$1"
+    )
 
 Remember to enable the FastCGI, alias and rewrite modules. This configuration
 binds the application to `/yourapplication`.  If you want the application to
diff --git a/flask/app.py b/flask/app.py
index 805dc166..ef2af73c 100644
--- a/flask/app.py
+++ b/flask/app.py
@@ -1547,7 +1547,7 @@ class Flask(_PackageBoundObject):
         :class:`tuple`          A tuple in the form ``(response, status,
                                 headers)`` where `response` is any of the
                                 types defined here, `status` is a string
-                                or an integer and `headers` is a list of
+                                or an integer and `headers` is a list or
                                 a dictionary with header values.
         ======================= ===========================================
 
diff --git a/flask/helpers.py b/flask/helpers.py
index 1e7c87f0..e59f7d3c 100644
--- a/flask/helpers.py
+++ b/flask/helpers.py
@@ -679,8 +679,13 @@ def find_package(import_name):
             filename = sys.modules[import_name].__file__
         package_path = os.path.abspath(os.path.dirname(filename))
         # package_path ends with __init__.py for a package
-        if loader.is_package(root_mod_name):
-            package_path = os.path.dirname(package_path)
+        if hasattr(loader, 'is_package'):
+            if loader.is_package(root_mod_name):
+                package_path = os.path.dirname(package_path)
+        else:
+            raise AttributeError(
+                ('%s.is_package() method is missing but is '
+                 'required by Flask of PEP 302 import hooks') % loader.__class__.__name__)
 
     site_parent, site_folder = os.path.split(package_path)
     py_prefix = os.path.abspath(sys.prefix)
diff --git a/flask/testsuite/config.py b/flask/testsuite/config.py
index 477c6db9..13e14d85 100644
--- a/flask/testsuite/config.py
+++ b/flask/testsuite/config.py
@@ -16,6 +16,7 @@ import pkgutil
 import unittest
 from contextlib import contextmanager
 from flask.testsuite import FlaskTestCase
+from flask._compat import PY2
 
 
 # config keys used for the ConfigTestCase
@@ -291,6 +292,18 @@ class InstanceTestCase(FlaskTestCase):
             if 'site_egg' in sys.modules:
                 del sys.modules['site_egg']
 
+    if PY2:
+        def test_meta_path_loader_without_is_package(self):
+            class Loader(object):
+                def find_module(self, name):
+                    return self
+            sys.meta_path.append(Loader())
+            try:
+                with self.assert_raises(AttributeError):
+                    flask.Flask(__name__)
+            finally:
+                sys.meta_path.pop()
+
 
 def suite():
     suite = unittest.TestSuite()