diff --git a/taxii2client/__init__.py b/taxii2client/__init__.py
index 548f279..edd90b5 100644
--- a/taxii2client/__init__.py
+++ b/taxii2client/__init__.py
@@ -159,7 +159,12 @@ class _TAXIIEndpoint(object):
         else:
             self._conn = _HTTPConnection(user, password, verify)
 
-        self.url = url
+        # Add trailing slash to TAXII endpoint if missing
+        # https://github.com/oasis-open/cti-taxii-client/issues/50
+        if url[-1] == "/":
+            self.url = url
+        else:
+            self.url = url + "/"
 
     def close(self):
         self._conn.close()

diff --git a/taxii2client/test/test_client.py b/taxii2client/test/test_client.py
index e363d27..db2ff84 100644
--- a/taxii2client/test/test_client.py
+++ b/taxii2client/test/test_client.py
@@ -960,3 +960,15 @@ def test_server_with_custom_properties(server):
     server.refresh()
     assert len(server.custom_properties) == 1
     assert server.custom_properties["x_example_com"] == "some value"
+
+
+@responses.activate
+def test_collection_missing_trailing_slash():
+    set_collection_response()
+    collection = Collection(COLLECTION_URL[:-1])
+    responses.add(responses.GET, GET_OBJECT_URL, GET_OBJECT_RESPONSE,
+                  status=200, content_type="%s; charset=utf-8" % MEDIA_TYPE_STIX_V20)
+
+    response = collection.get_object("indicator--252c7c11-daf2-42bd-843b-be65edca9f61")
+    indicator = response["objects"][0]
+    assert indicator["id"] == "indicator--252c7c11-daf2-42bd-843b-be65edca9f61"

Check for trailing slash in URLs
```
>>> collection = Collection('http://localhost:5000/trustgroup1/collections/91a7b528-80eb-42ed-a74d-c6fbd5a26116', user='user1', password='Password1')
>>> collection.get_object('indicator--252c7c11-daf2-42bd-843b-be65edca9f61')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/lu/Projects/cti-taxii-client/taxii2client/__init__.py", line 483, in get_object
    params=query_params)
  File "/home/lu/Projects/cti-taxii-client/taxii2client/__init__.py", line 876, in get
    resp.raise_for_status()
  File "/home/lu/.virtualenvs/cti-taxii-client/lib/python3.6/site-packages/requests/models.py", line 939, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 404 Client Error: NOT FOUND for url: http://localhost:5000/trustgroup1/collections/91a7b528-80eb-42ed-a74d-c6fbd5a26116objects/indicator--252c7c11-daf2-42bd-843b-be65edca9f61/
```

If I set up the collection with a `/` at the end of the url, it works fine because it's not trying to find a collection called `91a7b528-80eb-42ed-a74d-c6fbd5a26116objects`.

taxii2client/test/test_client.py::test_collection_missing_trailing_slash
taxii2client/test/test_client.py::test_server_discovery taxii2client/test/test_client.py::test_bad_json_response taxii2client/test/test_client.py::test_minimal_discovery_response taxii2client/test/test_client.py::test_discovery_with_no_default taxii2client/test/test_client.py::test_discovery_with_no_title taxii2client/test/test_client.py::test_api_root_no_title taxii2client/test/test_client.py::test_api_root_no_versions taxii2client/test/test_client.py::test_api_root_no_max_content_length taxii2client/test/test_client.py::test_api_root taxii2client/test/test_client.py::test_api_root_collections taxii2client/test/test_client.py::test_collection taxii2client/test/test_client.py::test_collection_unexpected_kwarg taxii2client/test/test_client.py::test_get_collection_objects taxii2client/test/test_client.py::test_get_object taxii2client/test/test_client.py::test_cannot_write_to_readonly_collection taxii2client/test/test_client.py::test_add_object_to_collection taxii2client/test/test_client.py::test_add_object_to_collection_dict taxii2client/test/test_client.py::test_add_object_to_collection_bin taxii2client/test/test_client.py::test_add_object_to_collection_badtype taxii2client/test/test_client.py::test_add_object_rases_error_when_collection_id_does_not_match_url taxii2client/test/test_client.py::test_cannot_read_from_writeonly_collection taxii2client/test/test_client.py::test_get_manifest taxii2client/test/test_client.py::test_get_status taxii2client/test/test_client.py::test_status_raw taxii2client/test/test_client.py::test_content_type_valid taxii2client/test/test_client.py::test_content_type_invalid taxii2client/test/test_client.py::test_url_filter_type taxii2client/test/test_client.py::test_filter_id taxii2client/test/test_client.py::test_filter_version taxii2client/test/test_client.py::test_filter_added_after taxii2client/test/test_client.py::test_filter_combo taxii2client/test/test_client.py::test_params_filter_unknown taxii2client/test/test_client.py::test_taxii_endpoint_raises_exception taxii2client/test/test_client.py::test_valid_content_type_for_connection taxii2client/test/test_client.py::test_invalid_content_type_for_connection taxii2client/test/test_client.py::test_status_missing_id_property taxii2client/test/test_client.py::test_status_missing_status_property taxii2client/test/test_client.py::test_status_missing_total_count_property taxii2client/test/test_client.py::test_status_missing_success_count_property taxii2client/test/test_client.py::test_status_missing_failure_count_property taxii2client/test/test_client.py::test_status_missing_pending_count_property taxii2client/test/test_client.py::test_collection_missing_id_property taxii2client/test/test_client.py::test_collection_missing_title_property taxii2client/test/test_client.py::test_collection_missing_can_read_property taxii2client/test/test_client.py::test_collection_missing_can_write_property taxii2client/test/test_client.py::test_conn_post_kwarg_errors taxii2client/test/test_client.py::test_user_agent_defaulting taxii2client/test/test_client.py::test_user_agent_overriding taxii2client/test/test_client.py::test_user_agent_enforcing1 taxii2client/test/test_client.py::test_user_agent_enforcing2 taxii2client/test/test_client.py::test_user_agent_enforcing3 taxii2client/test/test_client.py::test_header_merging taxii2client/test/test_client.py::test_header_merge_none taxii2client/test/test_client.py::test_collection_with_custom_properties taxii2client/test/test_client.py::test_status_with_custom_properties taxii2client/test/test_client.py::test_api_roots_with_custom_properties taxii2client/test/test_client.py::test_server_with_custom_properties