diff --git a/knip.ts b/knip.ts
index d23d42fe..3be3e653 100644
--- a/knip.ts
+++ b/knip.ts
@@ -34,6 +34,12 @@ export default {
     // then Knip will flag it as a false positive
     // https://github.com/webpro-nl/knip/issues/766
     "@vector-im/compound-web",
+    // Yarn plugins are allowed to depend on packages provided by the Yarn
+    // runtime. These shouldn't be listed in package.json, because plugins
+    // should work before Yarn even installs dependencies for the first time.
+    // https://yarnpkg.com/advanced/plugin-tutorial#what-does-a-plugin-look-like
+    "@yarnpkg/core",
+    "@yarnpkg/parsers",
     "matrix-widget-api",
   ],
   ignoreExportsUsedInFile: true,