1 files changed, 7 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 7cf371be68..946436f7f9 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -637,7 +637,7 @@ module ActiveRecord
           end
 
           def create_table_definition(*args)
-            PostgreSQL::TableDefinition.new(*args)
+            PostgreSQL::TableDefinition.new(self, *args)
           end
 
           def create_alter_table(name)
@@ -716,6 +716,12 @@ module ActiveRecord
           end
 
           def add_timestamps_for_alter(table_name, options = {})
+            options[:null] = false if options[:null].nil?
+
+            if !options.key?(:precision) && supports_datetime_with_precision?
+              options[:precision] = 6
+            end
+
             [add_column_for_alter(table_name, :created_at, :datetime, options), add_column_for_alter(table_name, :updated_at, :datetime, options)]
           end