diff --git a/swift3/middleware.py b/swift3/middleware.py
index 7650e187..c236277c 100644
--- a/swift3/middleware.py
+++ b/swift3/middleware.py
@@ -69,7 +69,8 @@ from swift3.request import Request
 from swift3.response import HTTPNoContent, HTTPOk, ErrorResponse, \
     AccessDenied, BucketAlreadyExists, BucketNotEmpty, EntityTooLarge, \
     InternalError, InvalidArgument, InvalidDigest, MalformedACLError, \
-    MethodNotAllowed, NoSuchBucket, NoSuchKey, S3NotImplemented
+    MethodNotAllowed, NoSuchBucket, NoSuchKey, S3NotImplemented, \
+    SignatureDoesNotMatch
 
 
 XMLNS_XSI = 'http://www.w3.org/2001/XMLSchema-instance'
@@ -231,7 +232,9 @@ class ServiceController(Controller):
         status = resp.status_int
 
         if status != HTTP_OK:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            if status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             else:
                 raise InternalError()
@@ -292,7 +295,9 @@ class BucketController(Controller):
         status = resp.status_int
 
         if status != HTTP_OK:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            if status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
@@ -358,7 +363,9 @@ class BucketController(Controller):
         status = resp.status_int
 
         if status != HTTP_CREATED and status != HTTP_NO_CONTENT:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            if status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_ACCEPTED:
                 raise BucketAlreadyExists(req.container_name)
@@ -375,7 +382,9 @@ class BucketController(Controller):
         status = resp.status_int
 
         if status != HTTP_NO_CONTENT:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            if status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
@@ -406,7 +415,9 @@ class ObjectController(Controller):
 
         if is_success(status):
             return resp
-        elif status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+        elif status == HTTP_UNAUTHORIZED:
+            raise SignatureDoesNotMatch()
+        elif status == HTTP_FORBIDDEN:
             raise AccessDenied()
         elif status == HTTP_NOT_FOUND:
             raise NoSuchKey(req.object_name)
@@ -433,7 +444,9 @@ class ObjectController(Controller):
         status = resp.status_int
 
         if status != HTTP_CREATED:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
@@ -467,7 +480,9 @@ class ObjectController(Controller):
         status = resp.status_int
 
         if status != HTTP_NO_CONTENT:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchKey(req.object_name)
@@ -508,7 +523,9 @@ class AclController(Controller):
                 # Method must be GET or the body wont be returned to the caller
                 req.environ['REQUEST_METHOD'] = 'GET'
                 return get_acl(req.access_key, headers)
-            elif status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            elif status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchKey(req.object_name)
@@ -524,7 +541,9 @@ class AclController(Controller):
             if is_success(status):
                 return get_acl(req.access_key, headers)
 
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
@@ -555,7 +574,9 @@ class AclController(Controller):
             status = resp.status_int
 
             if status != HTTP_ACCEPTED:
-                if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+                if status == HTTP_UNAUTHORIZED:
+                    raise SignatureDoesNotMatch()
+                elif status == HTTP_FORBIDDEN:
                     raise AccessDenied()
                 else:
                     raise InternalError()
@@ -576,7 +597,9 @@ class LocationController(Controller):
         status = resp.status_int
 
         if status != HTTP_OK:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
@@ -608,7 +631,9 @@ class LoggingStatusController(Controller):
         status = resp.status_int
 
         if status != HTTP_OK:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
@@ -770,7 +795,9 @@ class VersioningController(Controller):
         status = resp.status_int
 
         if status != HTTP_OK:
-            if status in (HTTP_UNAUTHORIZED, HTTP_FORBIDDEN):
+            if status == HTTP_UNAUTHORIZED:
+                raise SignatureDoesNotMatch()
+            elif status == HTTP_FORBIDDEN:
                 raise AccessDenied()
             elif status == HTTP_NOT_FOUND:
                 raise NoSuchBucket(req.container_name)
diff --git a/swift3/test/unit/test_swift3.py b/swift3/test/unit/test_swift3.py
index c63af8dc..793b8fba 100644
--- a/swift3/test/unit/test_swift3.py
+++ b/swift3/test/unit/test_swift3.py
@@ -204,7 +204,7 @@ class TestSwift3(unittest.TestCase):
 
     def test_service_GET_error(self):
         code = self._test_method_error('GET', '', swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('GET', '', swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')
         code = self._test_method_error('GET', '', swob.HTTPServerError)
@@ -235,7 +235,7 @@ class TestSwift3(unittest.TestCase):
 
     def test_bucket_GET_error(self):
         code = self._test_method_error('GET', '/bucket', swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('GET', '/bucket', swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')
         code = self._test_method_error('GET', '/bucket', swob.HTTPNotFound)
@@ -339,7 +339,7 @@ class TestSwift3(unittest.TestCase):
                                        headers={'Content-Length': '-1'})
         self.assertEqual(code, 'InvalidArgument')
         code = self._test_method_error('PUT', '/bucket', swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('PUT', '/bucket', swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')
         code = self._test_method_error('PUT', '/bucket', swob.HTTPAccepted)
@@ -357,7 +357,7 @@ class TestSwift3(unittest.TestCase):
     def test_bucket_DELETE_error(self):
         code = self._test_method_error('DELETE', '/bucket',
                                        swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('DELETE', '/bucket', swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')
         code = self._test_method_error('DELETE', '/bucket', swob.HTTPNotFound)
@@ -446,7 +446,7 @@ class TestSwift3(unittest.TestCase):
     def test_object_GET_error(self):
         code = self._test_method_error('GET', '/bucket/object',
                                        swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('GET', '/bucket/object',
                                        swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')
@@ -474,7 +474,7 @@ class TestSwift3(unittest.TestCase):
     def test_object_PUT_error(self):
         code = self._test_method_error('PUT', '/bucket/object',
                                        swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('PUT', '/bucket/object',
                                        swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')
@@ -524,7 +524,7 @@ class TestSwift3(unittest.TestCase):
     def test_object_DELETE_error(self):
         code = self._test_method_error('DELETE', '/bucket/object',
                                        swob.HTTPUnauthorized)
-        self.assertEquals(code, 'AccessDenied')
+        self.assertEquals(code, 'SignatureDoesNotMatch')
         code = self._test_method_error('DELETE', '/bucket/object',
                                        swob.HTTPForbidden)
         self.assertEquals(code, 'AccessDenied')