diff --git a/lib/galaxy/jobs/__init__.py b/lib/galaxy/jobs/__init__.py
index e6fd99f2340e..86098172de86 100644
--- a/lib/galaxy/jobs/__init__.py
+++ b/lib/galaxy/jobs/__init__.py
@@ -2001,13 +2001,13 @@ def fail(message=job.info, exception=None):
         # Once datasets are collected, set the total dataset size (includes extra files)
         for dataset_assoc in job.output_datasets:
             dataset = dataset_assoc.dataset.dataset
-            if not dataset.purged:
-                # assume all datasets in a job get written to the same objectstore
-                quota_source_info = dataset.quota_source_info
-                collected_bytes += dataset.set_total_size()
-            else:
+            # assume all datasets in a job get written to the same objectstore
+            quota_source_info = dataset.quota_source_info
+            collected_bytes += dataset.set_total_size()
+            if dataset.purged:
                 # Purge, in case job wrote directly to object store
                 dataset.full_delete()
+                collected_bytes = 0
 
         user = job.user
         if user and collected_bytes > 0 and quota_source_info is not None and quota_source_info.use:
diff --git a/lib/galaxy/model/store/__init__.py b/lib/galaxy/model/store/__init__.py
index 4880b83e7b96..1ea9fcf69855 100644
--- a/lib/galaxy/model/store/__init__.py
+++ b/lib/galaxy/model/store/__init__.py
@@ -665,9 +665,9 @@ def handle_dataset_object_edit(dataset_instance, dataset_attrs):
                                 assert file_source_root
                                 dataset_extra_files_path = os.path.join(file_source_root, dataset_extra_files_path)
                                 persist_extra_files(self.object_store, dataset_extra_files_path, dataset_instance)
-                            # Don't trust serialized file size
-                        dataset_instance.dataset.file_size = None
-                        dataset_instance.dataset.set_total_size()  # update the filesize record in the database
+                            # Only trust file size if the dataset is purged. If we keep the data we should check the file size.
+                            dataset_instance.dataset.file_size = None
+                            dataset_instance.dataset.set_total_size()  # update the filesize record in the database
 
                     if dataset_instance.deleted:
                         dataset_instance.dataset.deleted = True