Spring cacheable not synchronized

I have a singleton class (@Service annotated). This class has a method which takes 200/300ms to execute.

This method is annotated with @Cacheable and synchronized.

@Cacheable(value="nextPlaying", key = "#startingFrom.getYear() + #startingFrom.getMonth() + #startingFrom.getDay() + #startingFrom.getHours() + #startingFrom.getMinutes() + #locale.getLanguage()")
public synchronized List<Match> getNextPlaying(Date startingFrom, Locale locale)

By launching multiple threads calling this method I see that for these 200/300ms until the result isn't cached, it executes again and again the method until is cached. Seems that @Cacheable annotation doesn't take synchronized into account... Is this a bug?