Change language of searchbutton

Replies: 0

I’ve made a dutch translation for the Optimizer theme, but it doesn’t seem to work in the search-box. The standard-text in the searchbox says ‘Searching…’ instead of ‘Zoeken…’ and the button still says ‘Search’ instead of ‘Zoeken’. Where can I change it? Changing it in the .po languagefiles doesn’t seem to work.
With the standard 2017 theme buttons are in dutch.