diff --git a/isic/core/utils/db.py b/isic/core/utils/db.py
index 27ad5a49..74a1d473 100644
--- a/isic/core/utils/db.py
+++ b/isic/core/utils/db.py
@@ -7,7 +7,7 @@
 def lock_table_for_writes(cls: type[models.Model]):
     with transaction.atomic():
         cursor = transaction.get_connection().cursor()
-        cursor.execute(f"LOCK TABLE {cls._meta.db_table} IN SHARE MODE")
+        cursor.execute(f"LOCK TABLE {cls._meta.db_table} IN EXCLUSIVE MODE")
         try:
             yield
         finally: