The Oder-Neisse line was reaffirmed by a reunited Germany in the German-Polish Border Treaty , signed on 14 November 1990 . In the aftermath of the 1990 Treaty on the Final Settlement with Respect to Germany , the Oder-Neisse line was reaffirmed without any reservation with the German-Polish Border Treaty , signed on 14 November 1990 by re-united Germany and Poland .