--- title: "Omit for Discriminated Unions in TypeScript" url: https://daily.dev/posts/omit-for-discriminated-unions-in-typescript-ujl0mde1h source_url: https://tkdodo.eu/blog/omit-for-discriminated-unions-in-type-script type: article source: "TkDodo" author: "Dominik D" published: 2025-11-24T15:52:50.887Z updated: 2025-11-25T12:00:10.693Z tags: ["react", "typescript"] reading_time: 7 upvotes: 7 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Omit for Discriminated Unions in TypeScript **[TkDodo](https://daily.dev/sources/tkdodo)** · [@tkdodo](https://daily.dev/tkdodo) · 7 min read · 7 upvotes · 0 comments ## Summary TypeScript's built-in Omit utility type breaks discriminated unions by treating them as a whole rather than distributing over each union member. This causes type errors when building wrapper components that depend on discriminated union props. A distributive version using conditional types (T extends any ? Omit : never) preserves the union structure by applying Omit to each member individually. This solution also provides stricter type checking by constraining keys to those that actually exist on the type. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Distributive Conditional Types in TypeScript](https://daily.dev/posts/distributive-conditional-types-in-typescript-6tu0eqy5m) · RUBYLAND · 0 upvotes · 0 comments --- Tags: [#react](https://daily.dev/tags/react), [#typescript](https://daily.dev/tags/typescript) [View this post on daily.dev](https://daily.dev/posts/omit-for-discriminated-unions-in-typescript-ujl0mde1h)