diff --git a/test/reinject.test.ts b/test/reinject.test.ts
new file mode 100644
index 0000000..8e2e7fc
--- /dev/null
+++ b/test/reinject.test.ts
@@ -0,0 +1,81 @@
+import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from "fs";
+import { tmpdir } from "os";
+import { join } from "path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { buildReinjectBlocks, tryConsumeDeferredReinject } from "../src/reinject";
+import { createDefaultSettings } from "../src/settings";
+import { createInitialState, trackSkill } from "../src/state";
+
+const tempDirs: string[] = [];
+
+afterEach(() => {
+	for (const dir of tempDirs.splice(0)) {
+		rmSync(dir, { recursive: true, force: true });
+	}
+});
+
+function tempSkillDir(name: string): { filePath: string; baseDir: string } {
+	const root = mkdtempSync(join(tmpdir(), "pi-skill-reinject-deferred-"));
+	tempDirs.push(root);
+	const baseDir = join(root, name);
+	mkdirSync(baseDir, { recursive: true });
+	const filePath = join(baseDir, "SKILL.md");
+	writeFileSync(filePath, "# skill\n", "utf8");
+	return { filePath, baseDir };
+}
+
+function ctxWithNotify(): { ctx: never; notify: ReturnType<typeof vi.fn> } {
+	const notify = vi.fn();
+	return { notify, ctx: { hasUI: true, ui: { notify } } as never };
+}
+
+describe("deferred reinject loose fallback", () => {
+	it("(a) unregistered on disk with requireRegistered=false → block + info notify", () => {
+		const { filePath, baseDir } = tempSkillDir("loose");
+		const state = createInitialState();
+		trackSkill(state, { name: "loose", filePath, baseDir, source: "slash" });
+		state.pendingReinject = ["loose"];
+		const { ctx, notify } = ctxWithNotify();
+
+		const result = tryConsumeDeferredReinject(state, createDefaultSettings(), [], ctx);
+
+		expect(result?.message?.content).toContain('<skill name="loose"');
+		expect(notify).toHaveBeenCalledWith('skill-reinject: re-injected "loose" from disk', "info");
+	});
+
+	it("(b) unregistered on disk with requireRegistered=true → skip + warn", () => {
+		const { filePath, baseDir } = tempSkillDir("strict");
+		const state = createInitialState();
+		trackSkill(state, { name: "strict", filePath, baseDir, source: "slash" });
+		const settings = createDefaultSettings();
+		settings.requireRegistered = true;
+		const { ctx, notify } = ctxWithNotify();
+
+		const blocks = buildReinjectBlocks(["strict"], state, settings, [], ctx);
+
+		expect(blocks).toEqual([]);
+		expect(notify).toHaveBeenCalledWith(
+			'skill-reinject: skipped "strict" — no longer registered',
+			"warning",
+		);
+	});
+
+	it("(c) missing filePath on disk → skip + warn", () => {
+		const state = createInitialState();
+		trackSkill(state, {
+			name: "missing",
+			filePath: "/no/such/SKILL.md",
+			baseDir: "/no/such",
+			source: "slash",
+		});
+		const { ctx, notify } = ctxWithNotify();
+
+		const blocks = buildReinjectBlocks(["missing"], state, createDefaultSettings(), [], ctx);
+
+		expect(blocks).toEqual([]);
+		expect(notify).toHaveBeenCalledWith(
+			'skill-reinject: skipped "missing" — SKILL.md not found on disk',
+			"warning",
+		);
+	});
+});