A couple in Spain have started an online petition after registry officials refused to let them call their newborn son “Wolf.”

The father, Nako Javierre, says in a letter accompanying the petition that he and his wife Maria decided on the name because of “our love for this animal.”

But he says the Fuenlabrada registry office in Madrid earlier this month refused to accept the name because it could be “offensive” for their son. They later said “Lobo” was a surname in Spanish and could cause confusion.

The parents noted that the name is acceptable in other countries and hope to use the petition to back their argument in court. The petition had just over 2,000 supporters Thursday.

There was no immediate comment from officials.