diff --git a/declearn/metrics/_roc_auc.py b/declearn/metrics/_roc_auc.py
index a8a97dcc0a277081ba9fe92f098ba1dca92a3f80..4ed37a853cc57f5e12b99ed0ab8b5785d6712c4b 100644
--- a/declearn/metrics/_roc_auc.py
+++ b/declearn/metrics/_roc_auc.py
@@ -53,7 +53,9 @@ class BinaryRocAUC(Metric):
 
     Note that this class supports aggregating states from another
     BinaryRocAUC instance with different hyper-parameters into it,
-    unless its
+    unless its `bound` parameter is set - in which case thresholds
+    are not authorized to be dynamically updated, either at samples
+    processing or states-aggregating steps.
     """
 
     name: ClassVar[str] = "binary-roc"