diff --git a/django/core/handlers/wsgi.py b/django/core/handlers/wsgi.py
index d3632c77ed..2fd99921b8 100644
--- a/django/core/handlers/wsgi.py
+++ b/django/core/handlers/wsgi.py
@@ -242,10 +242,16 @@ class WSGIHandler(base.BaseHandler):
         # settings weren't available.
         if self._request_middleware is None:
             self.initLock.acquire()
-            # Check that middleware is still uninitialised.
-            if self._request_middleware is None:
-                self.load_middleware()
-            self.initLock.release()
+            try:
+                # Check that middleware is still uninitialised.
+                if self._request_middleware is None:
+                    self.load_middleware()
+            except:
+                # Unload whatever middleware we got
+                self._request_middleware = None
+                raise
+            finally:
+                self.initLock.release()
 
         set_script_prefix(base.get_script_name(environ))
         signals.request_started.send(sender=self.__class__)
diff --git a/tests/regressiontests/handlers/__init__.py b/tests/regressiontests/handlers/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/regressiontests/handlers/models.py b/tests/regressiontests/handlers/models.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/regressiontests/handlers/tests.py b/tests/regressiontests/handlers/tests.py
new file mode 100644
index 0000000000..5e84f71177
--- /dev/null
+++ b/tests/regressiontests/handlers/tests.py
@@ -0,0 +1,25 @@
+from django.utils import unittest
+from django.conf import settings
+from django.core.handlers.wsgi import WSGIHandler
+
+class HandlerTests(unittest.TestCase):
+
+    def test_lock_safety(self):
+        """
+        Tests for bug #11193 (errors inside middleware shouldn't leave
+        the initLock locked).
+        """
+        # Mangle settings so the handler will fail
+        old_middleware_classes = settings.MIDDLEWARE_CLASSES
+        settings.MIDDLEWARE_CLASSES = 42
+        # Try running the handler, it will fail in load_middleware
+        handler = WSGIHandler()
+        self.assertEqual(handler.initLock.locked(), False)
+        try:
+            handler(None, None)
+        except:
+            pass
+        self.assertEqual(handler.initLock.locked(), False)
+        # Reset settings
+        settings.MIDDLEWARE_CLASSES = old_middleware_classes
+