diff --git a/active_record/connection_adapters/postgresql/get_type_map.rb b/active_record/connection_adapters/postgresql/get_type_map.rb
index e313e44..8f4d894 100644
--- a/active_record/connection_adapters/postgresql/get_type_map.rb
+++ b/active_record/connection_adapters/postgresql/get_type_map.rb
@@ -3,7 +3,11 @@ module ActiveRecord
     module ConnectionAdapters
       module PostgreSQL
         def get_type_map
-          type_map
+          if Rails::VERSION::MAJOR == 4 && Rails::VERSION::MINOR == 0
+            ::ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::TYPE_MAP
+          else
+            type_map
+          end
         end
       end
     end
diff --git a/lib/postgresql_cursor.rb b/lib/postgresql_cursor.rb
index 2d3d2f9..faa58e7 100644
--- a/lib/postgresql_cursor.rb
+++ b/lib/postgresql_cursor.rb
@@ -8,5 +8,5 @@
 require 'active_record'
 require 'active_record/connection_adapters/postgresql_adapter'
 ActiveRecord::Base.extend(PostgreSQLCursor::ActiveRecord::SqlCursor)
-ActiveRecord::Relation.include(PostgreSQLCursor::ActiveRecord::Relation::CursorIterators)
-ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.include(PostgreSQLCursor::ActiveRecord::ConnectionAdapters::PostgreSQLTypeMap)
+ActiveRecord::Relation.send(:include, PostgreSQLCursor::ActiveRecord::Relation::CursorIterators)
+ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.send(:include, PostgreSQLCursor::ActiveRecord::ConnectionAdapters::PostgreSQLTypeMap)
diff --git a/lib/postgresql_cursor/active_record/connection_adapters/postgresql_type_map.rb b/lib/postgresql_cursor/active_record/connection_adapters/postgresql_type_map.rb
index ab4473b..d5cb8c4 100644
--- a/lib/postgresql_cursor/active_record/connection_adapters/postgresql_type_map.rb
+++ b/lib/postgresql_cursor/active_record/connection_adapters/postgresql_type_map.rb
@@ -5,7 +5,11 @@ module ConnectionAdapters
       module PostgreSQLTypeMap
         # Returns the private "type_map" needed for the cursor operation
         def get_type_map # :nodoc:
-          type_map
+          if Rails::VERSION::MAJOR == 4 && Rails::VERSION::MINOR == 0
+            ::ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::TYPE_MAP
+          else
+            type_map
+          end
         end
       end
     end