diff --git a/cyclonedds/builtin.py b/cyclonedds/builtin.py
index b207ebb5..cc3040ee 100644
--- a/cyclonedds/builtin.py
+++ b/cyclonedds/builtin.py
@@ -157,7 +157,7 @@ def __init__(self,
             ),
             listener=listener
         )
-        self._next_condition = ReadCondition(self, ViewState.Any | SampleState.NotRead | InstanceState.Any)
+        self._next_condition_states = ViewState.Any | SampleState.NotRead | InstanceState.Any
         if cqos:
             _CQos.cqos_destroy(cqos)
         self._make_constructors()
diff --git a/cyclonedds/sub.py b/cyclonedds/sub.py
index ca4ad891..c6cddb9a 100644
--- a/cyclonedds/sub.py
+++ b/cyclonedds/sub.py
@@ -140,8 +140,8 @@ def __init__(
                 _CQos.cqos_destroy(cqos)
         self._topic = topic
         self._topic_ref = topic._ref
-        self._next_condition = None
-        self._keepalive_entities = [self.subscriber, topic]
+        self._next_condition_states = ViewState.Any | SampleState.NotRead | InstanceState.Alive
+        self._keepalive_entities = [self.subscriber]
 
     @property
     def topic(self) -> Topic[_T]:
@@ -227,9 +227,7 @@ def read_next(self) -> Optional[_T]:
         DDSException
             If any error code is returned by the DDS API it is converted into an exception.
         """
-        self._next_condition = self._next_condition or \
-            ReadCondition(self, ViewState.Any | SampleState.NotRead | InstanceState.Alive)
-        samples = self.read(condition=self._next_condition)
+        samples = self.read(condition=ReadCondition(self, self._next_condition_states))
         if samples:
             return samples[0]
         return None
@@ -242,9 +240,7 @@ def take_next(self) -> Optional[_T]:
         DDSException
             If any error code is returned by the DDS API it is converted into an exception.
         """
-        self._next_condition = self._next_condition or \
-            ReadCondition(self, ViewState.Any | SampleState.NotRead | InstanceState.Alive)
-        samples = self.take(condition=self._next_condition)
+        samples = self.take(condition=ReadCondition(self, self._next_condition_states))
         if samples:
             return samples[0]
         return None