diff --git a/tests/scripts/uninstall.test.js b/tests/scripts/uninstall.test.js
index 69d851e3b..030a4ba83 100644
--- a/tests/scripts/uninstall.test.js
+++ b/tests/scripts/uninstall.test.js
@@ -17,7 +17,10 @@ const CURRENT_PACKAGE_VERSION = JSON.parse(
 const CURRENT_MANIFEST_VERSION = JSON.parse(
   fs.readFileSync(path.join(REPO_ROOT, 'manifests', 'install-modules.json'), 'utf8')
 ).version;
-const CLI_TIMEOUT_MS = 30000;
+// Windows CI file I/O is several times slower, and these cases run two full
+// CLI passes (install, then uninstall) over hundreds of files. install-apply
+// tests already scale their timeout the same way.
+const CLI_TIMEOUT_MS = process.platform === 'win32' ? 90000 : 30000;
 const {
   createInstallState,
   writeInstallState,