diff --git a/data/model/legacy.py b/data/model/legacy.py
index 311d566ad..94f799992 100644
--- a/data/model/legacy.py
+++ b/data/model/legacy.py
@@ -1668,6 +1668,7 @@ def _garbage_collect_storage(storage_id_whitelist):
   logger.debug('Garbage collecting derived storage from candidates: %s', storage_id_whitelist)
   with config.app_config['DB_TRANSACTION_FACTORY'](db):
     # Find out which derived storages will be removed, and add them to the whitelist
+    # The comma after ImageStorage.id is VERY important, it makes it a tuple, which is a sequence
     orphaned_from_candidates = list(orphaned_storage_query(ImageStorage.select(ImageStorage.id),
                                                            storage_id_whitelist,
                                                            (ImageStorage.id,)))
@@ -1707,22 +1708,32 @@ def _garbage_collect_storage(storage_id_whitelist):
     paths_to_remove = placements_query_to_paths_set(placements_to_remove.clone())
 
     # Remove the placements for orphaned storages
-    placements_subquery = list(placements_to_remove.clone().select(ImageStoragePlacement.id))
-    if len(placements_subquery) > 0:
-      (ImageStoragePlacement
-       .delete()
-       .where(ImageStoragePlacement.id << list(placements_subquery))
-       .execute())
+    placements_subquery = (placements_to_remove
+                           .clone()
+                           .select(ImageStoragePlacement.id)
+                           .alias('ps'))
+    inner = (ImageStoragePlacement
+             .select(placements_subquery.c.id)
+             .from_(placements_subquery))
+    placements_removed = (ImageStoragePlacement
+                          .delete()
+                          .where(ImageStoragePlacement.id << inner)
+                          .execute())
+    logger.debug('Removed %s image storage placements', placements_removed)
 
-    # Remove the all orphaned storages
-    orphaned_storages = list(orphaned_storage_query(ImageStorage.select(ImageStorage.id),
-                                                    storage_id_whitelist,
-                                                    (ImageStorage.id,)))
-    if len(orphaned_storages) > 0:
-      (ImageStorage
-       .delete()
-       .where(ImageStorage.id << orphaned_storages)
-       .execute())
+    # Remove all orphaned storages
+    # The comma after ImageStorage.id is VERY important, it makes it a tuple, which is a sequence
+    orphaned_storages = orphaned_storage_query(ImageStorage.select(ImageStorage.id),
+                                               storage_id_whitelist,
+                                               (ImageStorage.id,)).alias('osq')
+    orphaned_storage_inner = (ImageStorage
+                              .select(orphaned_storages.c.id)
+                              .from_(orphaned_storages))
+    storages_removed = (ImageStorage
+                        .delete()
+                        .where(ImageStorage.id << orphaned_storage_inner)
+                        .execute())
+    logger.debug('Removed %s image storage records', storages_removed)
 
   # We are going to make the conscious decision to not delete image storage blobs inside
   # transactions.