diff --git a/sklearn/cluster/tests/test_optics.py b/sklearn/cluster/tests/test_optics.py
index 1215746faa4c3..aaf5e8daf2919 100755
--- a/sklearn/cluster/tests/test_optics.py
+++ b/sklearn/cluster/tests/test_optics.py
@@ -449,3 +449,10 @@ def test_precomputed_dists():
 
     assert_allclose(clust1.reachability_, clust2.reachability_)
     assert_array_equal(clust1.labels_, clust2.labels_)
+
+def test_processing_order():
+    Y = [[0],[10],[-10],[25]]
+    clust = OPTICS(min_samples=3, max_eps=15).fit(Y)
+    assert_array_equal(clust.reachability_, [np.inf, 10, 10, 15])
+    assert_array_equal(clust.core_distances_, [10, 15, 20, 25])
+    assert_array_equal(clust.ordering_, [0, 1, 2, 3])