diff --git a/ckan/migration/versions/001_add_existing_tables.py b/ckan/migration/versions/001_add_existing_tables.py
index 2e43bb5e025..c4fba1a81c3 100644
--- a/ckan/migration/versions/001_add_existing_tables.py
+++ b/ckan/migration/versions/001_add_existing_tables.py
@@ -5,6 +5,8 @@
 
 
 def upgrade(migrate_engine):
+    # we specify the schema here, because of a clash with another 'state' table
+    # in the mdillon/postgis container
     meta = MetaData(schema='public')
 
     state = Table('state', meta,