diff --git a/swift/common/middleware/s3api/s3request.py b/swift/common/middleware/s3api/s3request.py
index ed453fb55f..2d1f7f2871 100644
--- a/swift/common/middleware/s3api/s3request.py
+++ b/swift/common/middleware/s3api/s3request.py
@@ -55,7 +55,7 @@ from swift.common.middleware.s3api.s3response import AccessDenied, \
     MissingContentLength, InvalidStorageClass, S3NotImplemented, InvalidURI, \
     MalformedXML, InvalidRequest, RequestTimeout, InvalidBucketName, \
     BadDigest, AuthorizationHeaderMalformed, SlowDown, \
-    AuthorizationQueryParametersError, ServiceUnavailable
+    AuthorizationQueryParametersError, ServiceUnavailable, BrokenMPU
 from swift.common.middleware.s3api.exception import NotS3Request, \
     BadSwiftRequest
 from swift.common.middleware.s3api.utils import utf8encode, \
@@ -1405,6 +1405,9 @@ class S3Request(swob.Request):
             if self.conf.ratelimit_as_client_error:
                 raise SlowDown(status='429 Slow Down')
             raise SlowDown()
+        if resp.status_int == HTTP_CONFLICT:
+            # TODO: validate that this actually came up out of SLO
+            raise BrokenMPU()
 
         raise InternalError('unexpected status code %d' % status)
 
diff --git a/swift/common/middleware/s3api/s3response.py b/swift/common/middleware/s3api/s3response.py
index 3ba4018a65..e32793f0fa 100644
--- a/swift/common/middleware/s3api/s3response.py
+++ b/swift/common/middleware/s3api/s3response.py
@@ -731,3 +731,9 @@ class UserKeyMustBeSpecified(ErrorResponse):
     _status = '400 Bad Request'
     _msg = 'The bucket POST must contain the specified field name. If it is ' \
            'specified, please check the order of the fields.'
+
+
+class BrokenMPU(ErrorResponse):
+    # This is very much a Swift-ism, and we wish we didn't need it
+    _status = '409 Conflict'
+    _msg = 'Multipart upload has broken segment data.'
diff --git a/test/unit/common/middleware/s3api/test_obj.py b/test/unit/common/middleware/s3api/test_obj.py
index 5acf191635..92e2482c16 100644
--- a/test/unit/common/middleware/s3api/test_obj.py
+++ b/test/unit/common/middleware/s3api/test_obj.py
@@ -307,6 +307,9 @@ class TestS3ApiObj(S3ApiTestCase):
         code = self._test_method_error('GET', '/bucket/object',
                                        swob.HTTPServiceUnavailable)
         self.assertEqual(code, 'ServiceUnavailable')
+        code = self._test_method_error('GET', '/bucket/object',
+                                       swob.HTTPConflict)
+        self.assertEqual(code, 'BrokenMPU')
 
         code = self._test_method_error(
             'GET', '/bucket/object',