diff --git a/lib/workers/repository/process/lookup/index.ts b/lib/workers/repository/process/lookup/index.ts
index f07743163ff8b477096f6a09b3042df90bb696e1..6f83a412b01519359183cf64d13599fd12a327ae 100644
--- a/lib/workers/repository/process/lookup/index.ts
+++ b/lib/workers/repository/process/lookup/index.ts
@@ -158,7 +158,7 @@ export async function lookupUpdates(
     res.sourceUrl =
       dependency.sourceUrl && dependency.sourceUrl.length
         ? dependency.sourceUrl
-        : null;
+        : /* istanbul ignore next */ null;
     if (dependency.sourceDirectory) {
       res.sourceDirectory = dependency.sourceDirectory;
     }