# Bad Influence story: Claude Fable 5.2 merges repeated code more often when told it owns the codebase

Active · 2 articles · 2 sources · First reported 11-10 00:34. Times are ET.
Story page: https://badinfluence.news/story/a5f139d2-1573-4fa7-959b-8c1aed9149ba

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[Bad Influence external source material begins]
Latest update (11-10 00:42): Anthropic's Fable 5.2 prompting guide suggests "This codebase is yours" for code changes

Overview: Anthropic says Claude Fable 5.2 merged repeated code in about half of its tries on small coding tasks when the prompt said the codebase was its own, and in under a tenth of tries without that wording. When the prompt was silent on ownership or described the code as someone else's, the model tended to add to existing structure instead. Simon Willison reports the finding from Anthropic's statement.

Willison also says Anthropic's updated prompting guide for Fable 5.2 recommends the line "This codebase is yours" for code changes, to make the model less cautious when improving existing code. He links to the guide's section on stating code ownership.

Coverage timeline (newest first):
1. 11-10 00:42 · Simon Willison · [Anthropic's Fable 5.2 prompting guide suggests "This codebase is yours" for code changes](https://badinfluence.news/items/giby8imt7e7qaar8gbbzueejj)
2. 11-10 00:34 · Simon Willison · [Claude Fable 5.2 merges repeated code more often when told it owns the codebase](https://badinfluence.news/items/w1vvf31zxddby9nc1qzigvrbr)
[Bad Influence external source material ends]

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