diff --git a/syncopy/datatype/continuous_data.py b/syncopy/datatype/continuous_data.py
index 4645d8e7c..fbcb82f86 100644
--- a/syncopy/datatype/continuous_data.py
+++ b/syncopy/datatype/continuous_data.py
@@ -728,15 +728,6 @@ class TimeLockData(ContinuousData):
     _defaultDimord = ["time", "channel"]
     _stackingDimLabel = "time"
 
-    # A `h5py.Dataset` holding the average of `data`, or `None` if not computed yet.
-    _avg = None
-
-    # A `h5py.Dataset` holding variance of `data`, or `None` if not computed yet.
-    _var = None
-
-    # A `h5py.Dataset` holding covariance of `data`, or `None` if not computed yet.
-    _cov = None
-
     # "Constructor"
     def __init__(self,
                  data=None,
@@ -781,6 +772,15 @@ def __init__(self,
                          channel=channel,
                          dimord=dimord)
 
+        # A `h5py.Dataset` holding the average of `data`, or `None` if not computed yet.
+        self._avg = None
+
+        # A `h5py.Dataset` holding variance of `data`, or `None` if not computed yet.
+        self._var = None
+
+        # A `h5py.Dataset` holding covariance of `data`, or `None` if not computed yet.
+        self._cov = None
+
     @property
     def avg(self):
         return self._avg