If the new obligation arisen from a novation does not come into existence or has been avoided by reason of illegality of its cause or of any circumstance of which the parties were not aware, the original obligation shall not be extinguished.
Civil Act — Article 504 (Case of non-extinguishment of original obligation)
민법 제504조
For AI agents and developers — get this article as JSON, with the English and current Korean effective dates and an outdated-translation flag, from the korea-law API or as an MCP tool:
https://mcp.apify.com?tools=kr-data/korea-law