Air fares are likely to increase this summer due to congestion at Amsterdam’s Schiphol airport, the Financieele Dagblad said on Thursday.

In addition, the overcrowding at the Amsterdam airport will force airlines to pare down their route networks if Schiphol growth is curbed, the paper said citing a study carried out by research bureau SEO for the European airport operators lobby group ACI Europe.

A similar situation occurred in 2014 when fliers paid €2.1bn more for airline tickets due to congestion at European airports, SEO said.

Schiphol is expected to reach its 500,000 flight movement cap this year. This means that there is no room for growth until 2020 and that will force airlines to increase their fares, SEO warned.