Fossil fuel incumbents—established firms steering carbon-intensive sectors—increasingly turn to digital technologies developed by ‘digital entrepreneurs’ for innovation and sustainability impact. Yet, how these regime actors engage with digital entrepreneurs and integrate their multifaceted offerings remains underexplored. Drawing on a longitudinal case study of a Norwegian oil firm, we examine corporate venture capital (CVC) investments as a specific form of niche-regime interactions. Our findings reveal that, although both CVC and digital technologies are widely lauded for their sustainability potential, the incumbent’s investments primarily aim to optimize and sustain existing oil and gas operations. Framed within a corporate narrative of a decarbonized future, the CVC investments in digital entrepreneurs tend to make conventional business operations smarter—that is, more efficient—but not radically greener. Our study highlights incumbents’ assimilative investment behaviour and underscores the untapped potential of niche-regime interactions and digital entrepreneurship in advancing sustainability transitions in hard-to-abate sectors.