diff --git a/lib/galaxy/managers/hdcas.py b/lib/galaxy/managers/hdcas.py
index 69e0d3dfdcd..42d44824515 100644
--- a/lib/galaxy/managers/hdcas.py
+++ b/lib/galaxy/managers/hdcas.py
@@ -41,7 +41,7 @@ def stream_dataset_collection(dataset_collection_instance, upstream_mod_zip=Fals
 
 
 def write_dataset_collection(dataset_collection_instance, archive):
-    if not dataset_collection_instance.collection.populated_optimized():
+    if not dataset_collection_instance.collection.populated_optimized:
         raise RequestParameterInvalidException("Attempt to write dataset collection that has not been populated yet")
     names, hdas = get_hda_and_element_identifiers(dataset_collection_instance)
     for name, hda in zip(names, hdas):