diff --git a/lib/fluent/plugin/out_sql.rb b/lib/fluent/plugin/out_sql.rb
index d55f9fe..23dfa79 100644
--- a/lib/fluent/plugin/out_sql.rb
+++ b/lib/fluent/plugin/out_sql.rb
@@ -206,7 +206,7 @@ def start
       end
 
       SQLOutput.const_set("BaseModel_#{rand(1 << 31)}", @base_model)
-      ActiveRecord::Base.establish_connection(config)
+      @base_model.establish_connection(config)
 
       # ignore tables if TableElement#init failed
       @tables.reject! do |te|
@@ -224,7 +224,7 @@ def formatted_to_msgpack_binary
     end
 
     def write(chunk)
-      ActiveRecord::Base.connection_pool.with_connection do
+      @base_model.connection_pool.with_connection do
 
         @tables.each { |table|
           tag = format_tag(chunk.metadata.tag)