Amazon announced today that it’s pumping another $4 billion into Claude AI maker Anthropic, bringing its total funding amount to $8 billion. This latest round follows $1.25 billion last September and another $2.75 billion in March.

Along with the money, Amazon wrote in its blog post that Amazon Web Services (AWS) would be named Anthropic’s “primary training partner” and that the OpenAI rival would use Trainium and Inferentia chips for future models.

The investment and deeper partnership align with previous reporting by Reuters that Claude will power Amazon’s new Alexa voice assistant. The improved Alexa — the release of which has been delayed — reportedly performed better with Claude than it did when using Amazon’s in-house model. The release of the revamped Alexa feature is now slated for 2025.

Amazon is at risk of falling further behind in the AI arms race compared to competitors like Microsoft and OpenAI. In the new version of Alexa, Amazon promised a more conversational tone, similar to OpenAI’s ChatGPT voice mode — but some beta users reported slow, stilted, and unhelpful responses. It also apparently has trouble turning on the lights.