If you're catching a train from Lyon to Lille, then you better factor in some extra time.
The service was the least punctual of all TGV routes last year, according to a new study by French consumer group 60 millions de Consommateurs.
The organisation weighed up the stats to find the least reliable TGV routes and bottom of the pile was the Lyon-Lille line, with a whopping 26.38 percent of trains failing to roll in on time.
It was followed by Marseille-Lille (25 percent late) and Lyon-Montpellier (23.33 percent).
Passengers can expect fewer delays on TGV trains heading east.
In 2015, the eastern TGV network had the best punctuality record.
The Reims-Paris line came out on top, with only 4.3 percent of trains late, with the Paris-Nancy line close on its heels (4.36 percent).
The services from Paris to Dijon, Nancy to Paris and Besançon to Paris all had lateness percentages of less than 5 percent.
For a full rankings, CLICK HERE.
And it wasn't just certain lines that suffered more delays than others, there were also certain times of the year that proved to be worse for TGV travellers.
So if you're taking a TGV train this month (July), don't expect it to be on time.
According to the study, TGV punctuality hits an annual low in July.
Between 2012 and 2015, 10.7 percent of TGVs were late nationwide. This figure rose to 12.8 percent for trains running in July.
In July 2015, 16.43 percent of trains failed to meet their schedule.
March wins the award for the most punctual month, with only 9.23 percent of TGVs running late over the last four years. The last month of summer, August, had a lower risk of late trains (10.06 percent) than the annual average.
The calculations were based on the SNCF's own data on punctuality.
The company records all delays of more than five minutes for journeys of less than ninety minutes, of more than 10 minutes for journeys between 90 minutes and three hours, and of more than 15 minutes for journeys longer than three hours.