The paper explores the role of suppliers in the process of environmental upgrading (EnvU) within global value chains (GVCs). Theoretical contributions to EnvU have highlighted, in particular, the role of global buyers in supporting the EnvU of products and processes, while limited attention has been given to suppliers as proactive actors within GVCs. This paper approaches EnvU through the lens of innovation and focuses on the agency of suppliers. Through the analysis of innovations developed within the leather GVC, with a special focus on the Arzignano cluster (Italy), the analysis shows how suppliers can autonomously develop sustainability strategies to maintain their competitiveness and achieve higher value in the GVC. However, results stress the limits of green strategies as buyers and suppliers do not share the same vision of how to foster sustainability.