The United States Tennis Association (USTA) issued an apology to the German Fed Cup team and fans on Saturday following an embarrassing anthem mix-up.
At the opening ceremony preceding the tie between the two nations in Hawaii, the abolished first verse of the visitors' national anthem - no longer used due to its association with Nazi Germany - was sung.
The USTA was quick to say sorry for the incident, releasing a statement via its official Twitter account.
It read: "The USTA extends a sincere apology to the German Fed Cup team and fans 4 [sic] the outdated National Anthem. This mistake will not occur again."
The German Tennis Federation replied: "we hope so", prompting a further apology from the USTA.