Allthough the Fokker D-21 was quite sucessful, the 830hp Mercury engined left it rather underpowered when compared with the Messerschmitt 109 and the Spitfire.
Therefore in 1940 the Dutch government approached Fokker with the request to produce a version of the D-21 with a more powerfull liquid cooled engine. The Dutch managed to procure a number of Rolls Royce Merlin III engines producing 1030hp.
Fokker matched this engine to a production D-21 airframe, producing the prototype for the Fokker D-22. The new aircraft was very similar to the D-21, having the same fixed undercariage.
The more powerful engine gave the D-22 an excellent performance and the D-22 served for many years in the Dutch air force helping maintain the Dutch neutrality.
In 1944 the D-22 was replaced with the Fokker D-26 fighter.