diff --git a/lib/workers/repository/init/vulnerability.ts b/lib/workers/repository/init/vulnerability.ts
index a2058d661e3a5823d2126f6b093815b1d7b31dd9..7c944932bb8201a43c524d3ac4bf205ce62baef1 100644
--- a/lib/workers/repository/init/vulnerability.ts
+++ b/lib/workers/repository/init/vulnerability.ts
@@ -129,7 +129,7 @@ export async function detectVulnerabilityAlerts(
       logger.warn({ err }, 'Error parsing vulnerability alert');
     }
   }
-  const alertPackageRules = [];
+  const alertPackageRules: PackageRule[] = [];
   for (const [fileName, files] of Object.entries(combinedAlerts)) {
     for (const [datasource, dependencies] of Object.entries(files)) {
       for (const [depName, currentValues] of Object.entries(dependencies)) {