diff --git a/spacy/tests/regression/test_issue3555.py b/spacy/tests/regression/test_issue3555.py
new file mode 100644
index 000000000..096b33367
--- /dev/null
+++ b/spacy/tests/regression/test_issue3555.py
@@ -0,0 +1,17 @@
+# coding: utf8
+from __future__ import unicode_literals
+
+import pytest
+from spacy.tokens import Doc, Token
+from spacy.matcher import Matcher
+
+
+@pytest.mark.xfail
+def test_issue3555(en_vocab):
+    """Test that custom extensions with default None don't break matcher."""
+    Token.set_extension("issue3555", default=None)
+    matcher = Matcher(en_vocab)
+    pattern = [{"LEMMA": "have"}, {"_": {"issue3555": True}}]
+    matcher.add("TEST", None, pattern)
+    doc = Doc(en_vocab, words=["have", "apple"])
+    matcher(doc)