_CONTEXT_: Recently, more and more developer communities are abandoning their legacy support forums, moving onto Stack Overflow. The motivations are diverse, yet they typically include achieving faster response time and larger visibility through the access to a modern and very successful infrastructure. One downside of migration, however, is that the history and the crowdsourced knowledge hosted at previous sites remain separated or even get lost if a community decides to abandon completely the legacy developer forum. _GOAL_: Adding to the body of evidence of existing research on best-answer prediction, here we show that, from a technical perspective, the content from existing developer forums might be automatically migrated to the Stack Overflow, although most of forums do not allow to mark a question as resolved, a distinctive feature of modern Q&A sites. _METHOD_: We trained a binary classifier with data from Stack Overflow and then tested it with data scraped from Docusign, a developer forum that has recently completed the move. _RESULTS_: Our findings show that best answers can be predicted with a good accuracy, only relying on shallow linguistic (text) features, such as answer length and the number of sentences, combined with other features like answer upvotes and age, which can be easily computed in near real-time. _CONCLUSIONS_: Results provide an initial yet positive evidence towards the automatic migration of crowdsourced knowledge from legacy forums to modern Q&A sites.