diff --git a/.github/scripts/ci-changes.cjs b/.github/scripts/ci-changes.cjs
index 0f817be60c35..b47199351c4d 100644
--- a/.github/scripts/ci-changes.cjs
+++ b/.github/scripts/ci-changes.cjs
@@ -5,11 +5,38 @@ const path = require("node:path");
 
 const root = path.resolve(__dirname, "../..");
 
+// Workflows no test reads. ci.yml defines the CI jobs, tests read release.yml
+// and web-preview.yml, and a workflow missing from this list runs everything.
+const INERT_WORKFLOWS = [
+  "agent-context-budget",
+  "deploy-relay",
+  "desktop-macos-preview",
+  "desktop-macos-preview-publish",
+  "issue-labels",
+  "mobile-android-apk",
+  "mobile-eas-preview",
+  "mobile-eas-preview-fork",
+  "mobile-eas-production",
+  "mobile-fingerprint-check",
+  "mobile-fingerprint-label",
+  "mobile-showcase-screenshots",
+  "pr-size",
+  "pr-vouch",
+  "publish-aur",
+  "relay-preview",
+  "relay-preview-cleanup",
+  "release-desktop",
+  "stale-needs-more-info",
+  "thread-transfer-report",
+  "windows-tests",
+];
+
 const INERT = [
   /^docs\//,
   /^\.(agents|cursor|vscode|devcontainer|macroscope|repos)\//,
   /^[^/]+\.md$/,
   /^LICENSE$/,
+  new RegExp(`^\\.github/workflows/(${INERT_WORKFLOWS.join("|")})\\.yml$`),
 ];
 
 // Shared test setup and vendored mobile dependencies affect every package.
diff --git a/scripts/check-changed.test.ts b/scripts/check-changed.test.ts
index b0e0fe01e851..3e22936389c1 100644
--- a/scripts/check-changed.test.ts
+++ b/scripts/check-changed.test.ts
@@ -46,6 +46,27 @@ describe("check:changed", () => {
     assert.deepStrictEqual(decide(["docs/user/install.md"], packages, false).affected, []);
   });
 
+  it("runs no package jobs for workflows that package tests do not read", () => {
+    const packages = readWorkspace();
+    const { affected, outputs } = decide([".github/workflows/pr-size.yml"], packages, false);
+    assert.deepStrictEqual(affected, []);
+    assert.isFalse(Object.values(outputs).some((value) => value === true));
+    assert.deepStrictEqual(
+      decide([".github/workflows/pr-size.yml", "apps/web/src/main.tsx"], packages, false).affected,
+      ["@t3tools/scripts", "@t3tools/web"],
+    );
+    for (const file of [
+      ".github/workflows/ci.yml",
+      ".github/workflows/release.yml",
+      ".github/workflows/web-preview.yml",
+      ".github/workflows/new-workflow.yml",
+      ".github/scripts/ci-changes.cjs",
+      ".github/actions/ci-changes/action.yml",
+    ]) {
+      assert.lengthOf(decide([file], packages, false).affected, packages.length, file);
+    }
+  });
+
   it.effect(
     "keeps weighted steps within the budget, in order, and serial steps one at a time",
     () =>