Papastathopoulos’ contract with Borussia Dortmund will keep him at the club until 2019.
“We are very pleased that we have managed, in Sokratis, to gain the long-term commitment of another of our top performers,” sporting director Michael Zorc said in a statement.
Sokratis added: “The city of Dortmund, BVB and the people here have become a second home for me and my family.
“I am very happy that I will still be able to wear the black and yellow shirt for a long time yet.”
