diff --git a/activerecord/test/cases/datatype_test_postgresql.rb b/activerecord/test/cases/datatype_test_postgresql.rb
index bff092b5d7e65dac8d6c8b8ee574da7e50acd75f..88fb6f738436fe33baeda5ad67b8e7baf9fceadb 100644
--- a/activerecord/test/cases/datatype_test_postgresql.rb
+++ b/activerecord/test/cases/datatype_test_postgresql.rb
@@ -26,6 +26,7 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
 
   def setup
     @connection = ActiveRecord::Base.connection
+    @connection.execute("set lc_monetary = 'C'")
 
     @connection.execute("INSERT INTO postgresql_arrays (commission_by_quarter, nicknames) VALUES ( '{35000,21000,18000,17000}', '{foo,bar,baz}' )")
     @first_array = PostgresqlArray.find(1)