diff --git a/spacy/tests/doc/test_span.py b/spacy/tests/doc/test_span.py
index 8cd4347c2..81c882967 100644
--- a/spacy/tests/doc/test_span.py
+++ b/spacy/tests/doc/test_span.py
@@ -19,6 +19,15 @@ def doc(en_tokenizer):
     return get_doc(tokens.vocab, [t.text for t in tokens], heads=heads, deps=deps)
 
 
+@pytest.fixture
+def doc_not_parsed(en_tokenizer):
+    text = "This is a sentence. This is another sentence. And a third."
+    tokens = en_tokenizer(text)
+    d = get_doc(tokens.vocab, [t.text for t in tokens])
+    d.is_parsed = False
+    return d
+
+
 def test_spans_sent_spans(doc):
     sents = list(doc.sents)
     assert sents[0].start == 0
@@ -34,6 +43,7 @@ def test_spans_root(doc):
     assert span.root.text == 'sentence'
     assert span.root.head.text == 'is'
 
+
 def test_spans_string_fn(doc):
     span = doc[0:4]
     assert len(span) == 4
@@ -41,6 +51,7 @@ def test_spans_string_fn(doc):
     assert span.upper_ == 'THIS IS A SENTENCE'
     assert span.lower_ == 'this is a sentence'
 
+
 def test_spans_root2(en_tokenizer):
     text = "through North and South Carolina"
     heads = [0, 3, -1, -2, -4]
@@ -49,12 +60,17 @@ def test_spans_root2(en_tokenizer):
     assert doc[-2:].root.text == 'Carolina'
 
 
-def test_spans_span_sent(doc):
+def test_spans_span_sent(doc, doc_not_parsed):
     """Test span.sent property"""
     assert len(list(doc.sents))
     assert doc[:2].sent.root.text == 'is'
     assert doc[:2].sent.text == 'This is a sentence .'
     assert doc[6:7].sent.root.left_edge.text == 'This'
+    # test on manual sbd
+    doc_not_parsed[0].is_sent_start = True
+    doc_not_parsed[5].is_sent_start = True
+    assert doc_not_parsed[1:3].sent == doc_not_parsed[0:5]
+    assert doc_not_parsed[10:14].sent == doc_not_parsed[5:]
 
 
 def test_spans_lca_matrix(en_tokenizer):