Personalizing a search query using social media

The invention relates to a method for personalizing a search of a search service. The search service comprises a search index with content items of a search type being used as first search results for first search queries issued by the client application and providing second search queries to be executed for retrieving second search results to be returned in reply to the first search queries. The method comprises using social media content items retrieved from social media services for extracting a set of keywords comprised by the social media content items. A second search query modified, wherein the modifying comprises adding keywords of the set keywords as additional search parameters of the determined second search query.