On 18 December 1908 it was decided to extend the line as far as the Baltic seaside resort of Arendsee, which was merged in 1938 with the neighbouring communities of Brunshaupten and Fulgen to form the Baltic Sea resort of Kühlungsborn ("Ostseebad Kühlungsborn"). This extension was opened on 12 May 1910, at the same time the Heiligendamm station was moved about 200 metres further south. In the same year, goods services were started; and trains now ran all year round. From 1 April 1920 it became part of the Deutsche Reichsbahn.