--- title: Ruby’s Ancestor Chain: Why prepend Cuts the Line | daily.dev description: Ruby's method lookup follows a well-defined ancestor chain. When modules are included, they are inserted after the class in the lookup order, with the most... canonical: https://daily.dev/posts/ruby-s-ancestor-chain-why-prepend-cuts-the-line-2petteqbx twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Ruby’s Ancestor Chain: Why prepend Cuts the Line | daily.dev og:description: Ruby's method lookup follows a well-defined ancestor chain. When modules are included, they are inserted after the class in the lookup order, with the most... og:url: https://daily.dev/posts/ruby-s-ancestor-chain-why-prepend-cuts-the-line-2petteqbx og:image: https://api.daily.dev/og/posts/2peTTeQBX.png og:image:alt: Ruby’s Ancestor Chain: Why prepend Cuts the Line og:image:width: 1200 og:image:height: 630 og:locale: 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. # Ruby’s Ancestor Chain: Why prepend Cuts the Line **[RUBYLAND](https://daily.dev/sources/rubyla)** · 3 min read · 0 upvotes · 0 comments ## Summary Ruby's method lookup follows a well-defined ancestor chain. When modules are included, they are inserted after the class in the lookup order, with the most recently included module taking priority. The prepend method behaves differently — it inserts a module before the class itself, giving it first access during method resolution. This distinction matters for Rails developers who rely on concerns, instrumentation wrappers, and monkey patches that depend on this mechanism. Using SomeClass.ancestors reveals the full lookup path and helps debug unexpected method behavior. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Inside Ruby’s Object Model](https://daily.dev/posts/inside-ruby-s-object-model-owqvili6x) · RUBYLAND · 1 upvotes · 0 comments - [A JavaScript developer's guide to Rails: Where Does Everything Come From?](https://daily.dev/posts/a-javascript-developer-s-guide-to-rails-where-does-everything-come-from--dkdcpuz9u) · thoughbot · 0 upvotes · 0 comments - [Ruby Instance Variables Are Not Inherited \(and Why That Breaks Your DSL\)](https://daily.dev/posts/ruby-instance-variables-are-not-inherited-and-why-that-breaks-your-dsl--gbn1gpbrt) · RUBYLAND · 1 upvotes · 0 comments - [Module extend self](https://daily.dev/posts/module-extend-self-ryxdgawob) · RUBYLAND · 0 upvotes · 0 comments - [Why Rails Runs Code Before Your Controller Action](https://daily.dev/posts/why-rails-runs-code-before-your-controller-action-dvv6dfecj) · Ruby Flow · 0 upvotes · 0 comments --- Tags: [#ruby](https://daily.dev/tags/ruby), [#rails](https://daily.dev/tags/rails) [View this post on daily.dev](https://daily.dev/posts/ruby-s-ancestor-chain-why-prepend-cuts-the-line-2petteqbx) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Ruby’s Ancestor Chain: Why prepend Cuts the Line","url":"https://daily.dev/posts/ruby-s-ancestor-chain-why-prepend-cuts-the-line-2petteqbx","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/ruby-s-ancestor-chain-why-prepend-cuts-the-line-2petteqbx"},"datePublished":"2026-06-08T02:26:46.299Z","dateModified":"2026-06-08T02:27:06.771Z","description":"Ruby's method lookup follows a well-defined ancestor chain. 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