diff --git a/README.rst b/README.rst
index 662e020..f8f8304 100644
--- a/README.rst
+++ b/README.rst
@@ -68,8 +68,8 @@ For more in-depth documentation, please see `https://stix2.readthedocs.io/ <http
 STIX 2 Technical Specification Support
 --------------------------------------
 
-This version of cti-python-stix2 brings support to `STIX Version 2.1 <https://docs.oasis-open.org/cti/stix/v2.1/cs01/stix-v2.1-cs01.html>`__
-published on 20 March 2020 currently at the Committee Specification (CS) level.
+This version of cti-python-stix2 brings support to `STIX Version 2.1 <https://docs.oasis-open.org/cti/stix/v2.1/cs02/stix-v2.1-cs02.html>`__
+published on 25 January 2021 currently at the Committee Specification (CS) 02 level.
 
 The stix2 Python library supports multiple versions of the STIX 2 Technical
 Specification. The library will be updated to support new Committee
diff --git a/stix2/test/v20/test_custom.py b/stix2/test/v20/test_custom.py
index 65daa93..e1eb600 100644
--- a/stix2/test/v20/test_custom.py
+++ b/stix2/test/v20/test_custom.py
@@ -438,8 +438,18 @@ class NewObservable():
 
 
 def test_custom_observable_object_1():
-    no = NewObservable(property1='something')
+    no = NewObservable(
+        property1='something',
+        extensions={
+            'archive-ext': stix2.v20.observables.ArchiveExt(
+                contains_refs=['file--e277603e-1060-5ad4-9937-c26c97f1ca68'],
+                version='2.0',
+                comment='for real',
+            )
+        }
+    )
     assert no.property1 == 'something'
+    assert no.extensions['archive-ext'].comment == 'for real'
 
 
 def test_custom_observable_object_2():