diff --git a/.changeset/9319-ui-library-prompt-section-numbering.md b/.changeset/9319-ui-library-prompt-section-numbering.md
new file mode 100644
index 0000000000..952d5a604a
--- /dev/null
+++ b/.changeset/9319-ui-library-prompt-section-numbering.md
@@ -0,0 +1,34 @@
+---
+---
+
+Renumber the `## N.` sections of `.github/prompts/ui-library.prompt.md` so they run
+`1, 2, 3, 4` instead of `1, 3, 4, 5` (objectui#9319). Instruction files only; no package is
+released by this change.
+
+**`## 2` was never written — it was not deleted.** The file has exactly one commit in its
+entire history, `4e7737788` ("refactor: remove outdated prompts and add new component
+development context"), and there it is a pure creation: `new file mode`, `@@ -0,0 +1,66 @@`,
+zero deletion lines. The headings read `1, 3, 4, 5` in that first commit and have never read
+anything else. A pickaxe for a `## 2` heading over the whole path across every ref returns no
+commit at all, while the same pickaxe for `## 3` returns that creating commit — so the search
+would have found a deletion had one happened. Nor is the file a condensation of one of the 17
+prompt files that same commit deleted: none of them contained the phrase "Core Philosophy",
+in a run where a control phrase ("Shadcn") hit nine of them.
+
+So the gap records nothing absent. There is no section 2 to restore and none is added — the
+same finding, and the same repair, that objectui#9145 reached for this file family's letter
+runs: "It was not dropped... there is no `C` category to restore." The two sibling prompts
+born in that same commit are numbered contiguously (`component.prompt.md` `0`–`4`,
+`engine.prompt.md` `1`–`7`); only this file skipped, which is what a hand-numbering slip
+looks like.
+
+Nothing cites these numbers, measured three ways, each against a control that hit: the five
+`§` cross-references in `.github/prompts/**` all point at `component.prompt.md` (`§2.A`,
+`§B`, `§E`) and none at this file; no tracked text contains any of its heading anchor slugs
+(`#3-component-standards` and its siblings), in a run where `#development-workflow` hit two
+files; and no tracked text pairs "ui-library" with a section reference. `check:prompt-keys`
+parses this file's four `## N.` sections and validates the `### A./B./C.` run under
+Component Standards, but it uses the section number only as a label and, by objectui#9145's
+explicit scoping, "the `## N.` numbers themselves are a different claim and are not judged" —
+so the renumbering moves no assertion. Only the four heading lines changed; the file's seven
+numbered list items are untouched.
diff --git a/.github/prompts/ui-library.prompt.md b/.github/prompts/ui-library.prompt.md
index 7a07b96fc2..f42bc30488 100644
--- a/.github/prompts/ui-library.prompt.md
+++ b/.github/prompts/ui-library.prompt.md
@@ -14,7 +14,7 @@
 ---
 
 
-## 3. Component Standards
+## 2. Component Standards
 
 ### A. The "cn" Pattern
 Every component **MUST** accept `className` and merge it using `cn()` (clsx + tailwind-merge).
@@ -47,7 +47,7 @@ Theme is controlled via CSS variables in `globals.css` (in the consumer app or i
 
 ---
 
-## 4. Development Workflow
+## 3. Development Workflow
 
 1.  **Add Primitive:** Use Shadcn CLI (or manual copy) to add atoms.
     *   `npx shadcn-ui@latest add dropdown-menu`
@@ -56,7 +56,7 @@ Theme is controlled via CSS variables in `globals.css` (in the consumer app or i
 
 ---
 
-## 5. Visual Standards
+## 4. Visual Standards
 
 *   **Typography:** Inter (default). Headings tight tracking, strict scale.
 *   **Borders:** Subtle (`border-zinc-200` light / `border-zinc-800` dark).