The Canadian Grand Prix has been dropped from the Formula One calendar for the second year in a row.

The cause is once again travel restrictions Canada has put in place to help prevent the spread of Covid-19, specifically the mandatory 14-day quarantine period international travelers need to make upon entering the country.

The Canadian race was scheduled for June 13. In its place will be a special Turkish Grand Prix, F1 organizers confirmed on Wednesday. The organizers are working with promoters to ensure anyone with tickets for either the 2020 or 2021 Canadian races receives a refund or a ticket to next year's race.

The Turkish race, which until 2011 was a regular on the F1 calendar, was also held last year to fill in for a canceled race.

This isn't the first time that the 2021 calendar has been reshuffled. The Australian Grand Prix, which normally opens the season, was moved down to November from March, with the Bahrain Grand Prix moved up to fill the gap. And a special Emilia Romagna Grand Prix was held last week to fill in for the canceled Chinese Grand Prix. This weekend will also be a special Portuguese Grand Prix which fills in for a Vietnamese Grand Prix which never made it past the planning stage.

F1 organizers are still hopeful of hosting a record 23 rounds in 2021. The record is made possible thanks to the addition of a new Saudi Arabian Grand Prix and the return of the Dutch Grand Prix.

To ensure safety, F1 participants operate in a bubble, with drivers and staff regularly tested. Approximately 78,000 tests conducted last year saw only 78 positive results, a rate of 0.1%. So far this season over 12,000 tests have been conducted with 14 positive cases again a rate of 0.1%.