diff --git a/consumer_group.go b/consumer_group.go
index 9c681d713..aae6599ca 100644
--- a/consumer_group.go
+++ b/consumer_group.go
@@ -514,6 +514,8 @@ type ConsumerGroupSession interface {
 	MarkOffset(topic string, partition int32, offset int64, metadata string)
 
 	// Commit the offset to the backend
+	//
+	// Note: calling Commit performs a blocking synchronous operation.
 	Commit()
 
 	// ResetOffset resets to the provided offset, alongside a metadata string that