return etag error if checksum and etag aren't equal
diff --git a/openstack/objectstorage/v1/objects/requests.go b/openstack/objectstorage/v1/objects/requests.go
index 2123dd9..c2fbaae 100644
--- a/openstack/objectstorage/v1/objects/requests.go
+++ b/openstack/objectstorage/v1/objects/requests.go
@@ -240,6 +240,7 @@
 			res.Err = err
 			return res
 		}
+		res.Err = fmt.Errorf("Local checksum does not match API ETag header")
 	}
 
 	return res