diff --git a/clickhouse_sqlalchemy/ext/clauses.py b/clickhouse_sqlalchemy/ext/clauses.py
index 448bf104..f745e52a 100644
--- a/clickhouse_sqlalchemy/ext/clauses.py
+++ b/clickhouse_sqlalchemy/ext/clauses.py
@@ -49,7 +49,7 @@ class Lambda(ColumnElement):
     __visit_name__ = 'lambda'
 
     def __init__(self, func):
-        if not util.callable(func):
+        if not callable(func):
             raise exc.ArgumentError('func must be callable')
 
         self.type = type_api.NULLTYPE
diff --git a/clickhouse_sqlalchemy/sql/schema.py b/clickhouse_sqlalchemy/sql/schema.py
index bc1dec18..85b495cb 100644
--- a/clickhouse_sqlalchemy/sql/schema.py
+++ b/clickhouse_sqlalchemy/sql/schema.py
@@ -12,9 +12,7 @@
 
 
 class Table(TableBase):
-    def drop(self, bind=None, checkfirst=False, if_exists=False):
-        if bind is None:
-            bind = self.bind
+    def drop(self, bind, checkfirst=False, if_exists=False):
         bind._run_ddl_visitor(ddl.SchemaDropper, self,
                               checkfirst=checkfirst, if_exists=if_exists)
 
@@ -115,14 +113,10 @@ def __repr__(self):
 
         return 'MaterializedView(%s)' % ', '.join(args)
 
-    def create(self, bind=None, checkfirst=False, if_not_exists=False):
-        if bind is None:
-            bind = self.bind
+    def create(self, bind, checkfirst=False, if_not_exists=False):
         bind._run_ddl_visitor(ddl.SchemaGenerator, self, checkfirst=checkfirst,
                               if_not_exists=if_not_exists)
 
-    def drop(self, bind=None, checkfirst=False, if_exists=False):
-        if bind is None:
-            bind = self.bind
+    def drop(self, bind, checkfirst=False, if_exists=False):
         bind._run_ddl_visitor(ddl.SchemaDropper, self, checkfirst=checkfirst,
                               if_exists=if_exists)