diff --git a/.circleci/config.yml b/.circleci/config.yml
index e3d5b29c..007b5fb2 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -10,6 +10,7 @@ workflows:
           name: Python 3.5
           docker-image: cimg/python:3.5
           skip-sse-contract-tests: true  # the test service app has dependencies that aren't available in 3.5, which is EOL anyway
+          skip-contract-tests: true  # the test service app has dependencies that aren't available in 3.5, which is EOL anyway
       - test-linux:
           name: Python 3.6
           docker-image: cimg/python:3.6
@@ -46,6 +47,9 @@ jobs:
       skip-sse-contract-tests:
         type: boolean
         default: false
+      skip-contract-tests:
+        type: boolean
+        default: false
     docker:
       - image: <<parameters.docker-image>>
       - image: redis
@@ -109,13 +113,16 @@ jobs:
               name: run SSE contract tests
               command: cd sse-contract-tests && make run-contract-tests
 
-      - run: make build-contract-tests
-      - run:
-          command: make start-contract-test-service
-          background: true
-      - run:
-          name: run contract tests
-          command: TEST_HARNESS_PARAMS="-junit test-reports/contract-tests-junit.xml" make run-contract-tests
+      - unless:
+          condition: <<parameters.skip-contract-tests>>
+          steps:
+          - run: make build-contract-tests
+          - run:
+              command: make start-contract-test-service
+              background: true
+          - run:
+              name: run contract tests
+              command: TEST_HARNESS_PARAMS="-junit test-reports/contract-tests-junit.xml" make run-contract-tests
 
       - store_test_results:
           path: test-reports
diff --git a/contract-tests/client_entity.py b/contract-tests/client_entity.py
index f3bf22fc..5d2d5220 100644
--- a/contract-tests/client_entity.py
+++ b/contract-tests/client_entity.py
@@ -6,39 +6,36 @@
 sys.path.insert(1, os.path.join(sys.path[0], '..'))
 from ldclient import *
 
-def millis_to_seconds(t):
-    return None if t is None else t / 1000
-
 
 class ClientEntity:
     def __init__(self, tag, config):
         self.log = logging.getLogger(tag)
         opts = {"sdk_key": config["credential"]}
 
-        if "streaming" in config:
+        if config.get("streaming") is not None:
             streaming = config["streaming"]
-            if "baseUri" in streaming:
+            if streaming.get("baseUri") is not None:
                 opts["stream_uri"] = streaming["baseUri"]
             if streaming.get("initialRetryDelayMs") is not None:
                 opts["initial_reconnect_delay"] = streaming["initialRetryDelayMs"] / 1000.0
 
-        if "events" in config:
+        if config.get("events") is not None:
             events = config["events"]
-            if "baseUri" in events:
+            if events.get("baseUri") is not None:
                 opts["events_uri"] = events["baseUri"]
-            if events.get("capacity", None) is not None:
+            if events.get("capacity") is not None:
                 opts["events_max_pending"] = events["capacity"]
             opts["diagnostic_opt_out"] = not events.get("enableDiagnostics", False)
             opts["all_attributes_private"] = events.get("allAttributesPrivate", False)
             opts["private_attribute_names"] = events.get("globalPrivateAttributes", {})
-            if "flushIntervalMs" in events:
+            if events.get("flushIntervalMs") is not None:
                  opts["flush_interval"] = events["flushIntervalMs"] / 1000.0
-            if "inlineUsers" in events:
+            if events.get("inlineUsers") is not None:
                 opts["inline_users_in_events"] = events["inlineUsers"]
         else:
             opts["send_events"] = False
 
-        start_wait = config.get("startWaitTimeMs", 5000)
+        start_wait = config.get("startWaitTimeMs") or 5000
         config = Config(**opts)
 
         self.client = client.LDClient(config, start_wait / 1000.0)
diff --git a/contract-tests/requirements.txt b/contract-tests/requirements.txt
index f55a4204..0018e4c8 100644
--- a/contract-tests/requirements.txt
+++ b/contract-tests/requirements.txt
@@ -1,2 +1,2 @@
-Flask==1.1.4
+Flask==2.0.3
 urllib3>=1.22.0
diff --git a/contract-tests/service.py b/contract-tests/service.py
index b4728867..d9f8e0a5 100644
--- a/contract-tests/service.py
+++ b/contract-tests/service.py
@@ -4,7 +4,7 @@
 import logging
 import os
 import sys
-from flask import Flask, request, jsonify
+from flask import Flask, request
 from flask.logging import default_handler
 from logging.config import dictConfig
 from werkzeug.exceptions import HTTPException
@@ -132,7 +132,7 @@ def delete_client(id):
         return ('', 404)
 
     client.close()
-    return ('', 204)
+    return ('', 202)
 
 if __name__ == "__main__":
     port = default_port
diff --git a/ldclient/impl/evaluator.py b/ldclient/impl/evaluator.py
index d019f10d..0fa9f088 100644
--- a/ldclient/impl/evaluator.py
+++ b/ldclient/impl/evaluator.py
@@ -243,7 +243,12 @@ def _bucket_user(seed, user, key, salt, bucket_by):
     return result
 
 def _bucketable_string_value(u_value):
-    return str(u_value) if isinstance(u_value, (str, int)) else None
+    if isinstance(u_value, bool):
+        return None
+    elif isinstance(u_value, (str, int)):
+        return str(u_value)
+
+    return None
 
 def _clause_matches_user_no_segments(clause, user):
     u_value, should_pass = _get_user_attribute(user, clause.get('attribute'))
diff --git a/ldclient/impl/integrations/redis/redis_big_segment_store.py b/ldclient/impl/integrations/redis/redis_big_segment_store.py
index 35b42b71..d3b4b767 100644
--- a/ldclient/impl/integrations/redis/redis_big_segment_store.py
+++ b/ldclient/impl/integrations/redis/redis_big_segment_store.py
@@ -26,7 +26,10 @@ def __init__(self, url: str, prefix: Optional[str], max_connections: int):
     def get_metadata(self) -> BigSegmentStoreMetadata:
         r = redis.Redis(connection_pool=self._pool)
         value = r.get(self._prefix + self.KEY_LAST_UP_TO_DATE)
-        return BigSegmentStoreMetadata(None if value is None else int(value))
+        if value is None:
+            return BigSegmentStoreMetadata(None)
+
+        return BigSegmentStoreMetadata(int(value))
 
     def get_membership(self, user_hash: str) -> Optional[dict]:
         r = redis.Redis(connection_pool=self._pool)
diff --git a/ldclient/impl/integrations/test_data/test_data_source.py b/ldclient/impl/integrations/test_data/test_data_source.py
index db3ac729..e6272925 100644
--- a/ldclient/impl/integrations/test_data/test_data_source.py
+++ b/ldclient/impl/integrations/test_data/test_data_source.py
@@ -5,11 +5,13 @@
 
 class _TestDataSource():
 
-    def __init__(self, feature_store, test_data):
+    def __init__(self, feature_store, test_data, ready):
         self._feature_store = feature_store
         self._test_data = test_data
+        self._ready = ready
 
     def start(self):
+        self._ready.set()
         self._feature_store.init(self._test_data._make_init_data())
 
     def stop(self):
diff --git a/ldclient/integrations/test_data.py b/ldclient/integrations/test_data.py
index a159eb12..0030cde6 100644
--- a/ldclient/integrations/test_data.py
+++ b/ldclient/integrations/test_data.py
@@ -51,7 +51,7 @@ def __init__(self):
         self._instances = []
 
     def __call__(self, config, store, ready):
-        data_source = _TestDataSource(store, self)
+        data_source = _TestDataSource(store, self, ready)
         try:
             self._lock.lock()
             self._instances.append(data_source)
@@ -485,7 +485,7 @@ def and_match(self, attribute: str, *values) -> 'FlagRuleBuilder':
         """
         self._clauses.append({
                 'attribute': attribute,
-                'operator': 'in',
+                'op': 'in',
                 'values': list(values),
                 'negate': False
             })
@@ -508,7 +508,7 @@ def and_not_match(self, attribute: str, *values) -> 'FlagRuleBuilder':
         """
         self._clauses.append({
                 'attribute': attribute,
-                'operator': 'in',
+                'op': 'in',
                 'values': list(values),
                 'negate': True
             })
diff --git a/sse-contract-tests/requirements.txt b/sse-contract-tests/requirements.txt
index 2d1d2a7b..0018e4c8 100644
--- a/sse-contract-tests/requirements.txt
+++ b/sse-contract-tests/requirements.txt
@@ -1,2 +1,2 @@
-Flask==2.0.2
+Flask==2.0.3
 urllib3>=1.22.0
diff --git a/sse-contract-tests/service.py b/sse-contract-tests/service.py
index 6d07fc59..389b1a1f 100644
--- a/sse-contract-tests/service.py
+++ b/sse-contract-tests/service.py
@@ -81,7 +81,7 @@ def delete_stream(id):
     if stream is None:
         return ('', 404)
     stream.close()
-    return ('', 204)
+    return ('', 202)
 
 if __name__ == "__main__":
     port = default_port
diff --git a/testing/integrations/test_test_data_source.py b/testing/integrations/test_test_data_source.py
index e0db1208..47f0d025 100644
--- a/testing/integrations/test_test_data_source.py
+++ b/testing/integrations/test_test_data_source.py
@@ -285,7 +285,7 @@ def test_flagbuilder_can_build():
                 'clauses': [
                     {'attribute': 'country',
                     'negate': False,
-                    'operator': 'in',
+                    'op': 'in',
                     'values': ['fr']
                     }
                 ],
@@ -297,3 +297,35 @@ def test_flagbuilder_can_build():
     }
 
     assert flag._build(1) == expected_result
+
+def test_flag_can_evaluate_rules():
+    td = TestData.data_source()
+    store = InMemoryFeatureStore()
+
+    client = LDClient(config=Config('SDK_KEY',
+                      update_processor_class = td,
+                      send_events = False,
+                      feature_store = store))
+
+    td.update(td.flag(key='test-flag')
+                .fallthrough_variation(False)
+                .if_match('firstName', 'Mike')
+                .and_not_match('country', 'gb')
+                .then_return(True))
+
+    # user1 should satisfy the rule (matching firstname, not matching country)
+    user1 = { 'key': 'user1', 'firstName': 'Mike', 'country': 'us' }
+    eval1 = client.variation_detail('test-flag', user1, default='default')
+
+    assert eval1.value == True
+    assert eval1.variation_index == 0
+    assert eval1.reason['kind'] == 'RULE_MATCH'
+
+    # user2 should NOT satisfy the rule (not matching firstname despite not matching country)
+    user2 = { 'key': 'user2', 'firstName': 'Joe', 'country': 'us' }
+    eval2 = client.variation_detail('test-flag', user2, default='default')
+
+    assert eval2.value == False
+    assert eval2.variation_index == 1
+    assert eval2.reason['kind'] == 'FALLTHROUGH'
+