diff --git a/sqlaload/schema.py b/sqlaload/schema.py
index 693d1c5..5a70b76 100644
--- a/sqlaload/schema.py
+++ b/sqlaload/schema.py
@@ -12,9 +12,6 @@ from migrate.versioning.util import construct_engine
 log = logging.getLogger(__name__)
 lock = RLock()
 
-TABLES = defaultdict(dict)
-INDEXES = dict()
-
 def connect(url):
     """ Create an engine for the given database URL. """
     kw = {}
@@ -27,6 +24,8 @@ def connect(url):
     meta = MetaData()
     meta.bind = engine
     engine._metadata = meta
+    engine._tables = dict()
+    engine._indexes = dict()
     return engine
 
 def create_table(engine, table_name):
@@ -36,14 +35,14 @@ def create_table(engine, table_name):
         col = Column('id', Integer, primary_key=True)
         table.append_column(col)
         table.create(engine)
-        TABLES[engine][table_name] = table
+        engine._tables[table_name] = table
         return table
 
 def load_table(engine, table_name):
     with lock:
         log.debug("Loading table: %s on %r" % (table_name, engine))
         table = Table(table_name, engine._metadata, autoload=True)
-        TABLES[engine][table_name] = table
+        engine._tables[table_name] = table
         return table
 
 def get_table(engine, table_name):
@@ -52,8 +51,8 @@ def get_table(engine, table_name):
         engine = engine.engine
     
     with lock:
-        if table_name in TABLES[engine]:
-            return TABLES[engine][table_name]
+        if table_name in engine._tables:
+            return engine._tables[table_name]
         if engine.has_table(table_name):
             return load_table(engine, table_name)
         else:
@@ -65,14 +64,14 @@ def drop_table(engine, table_name):
         engine = engine.engine
 
     with lock:
-        if table_name in TABLES[engine]:
-            table = TABLES[engine][table_name]
+        if table_name in engine._tables:
+            table = engine._tables[table_name]
         elif engine.has_table(table_name):
             table = Table(table_name, engine._metadata)
         else:
             return
         table.drop(engine)
-        TABLES[engine].pop(table_name, None)
+        engine._tables.pop(table_name, None)
 
 def _guess_type(sample):
     if isinstance(sample, bool):
@@ -113,14 +112,14 @@ def create_index(engine, table, columns, name=None):
         if not name:
             sig = abs(hash('||'.join(columns)))
             name = 'ix_%s_%s' % (table.name, sig)
-        if name in INDEXES:
-            return INDEXES[name]
+        if name in engine._indexes:
+            return engine._indexes[name]
         try:
             columns = [table.c[c] for c in columns]
             idx = Index(name, *columns)
             idx.create(engine)
         except:
             idx = None
-        INDEXES[name] = idx
+        engine._indexes[name] = idx
         return idx