Generative AI systems like ChatGPT can collaborate with humans on complex decision-making tasks. Yet, little is known about how AI-based decision support affects team decision-making processes and outcomes (Zercher et al., 2023). Research in the field of hidden profiles has shaped our understanding of challenges in team decision-making like the shared information bias (Lu et al., 2012). To explore the effect of AI-based team decision support on information sharing and team decision quality we conducted an experimental-control group design with two experimental conditions in a laboratory setting in a hidden profile scenario. While teams in the control condition did not receive any decision support, teams in the first experimental condition had access to a fully informed AI system, and in the second experimental condition, one team member was replaced by a partially informed AI system.