diff --git a/lib/workers/repository/process/lookup/index.ts b/lib/workers/repository/process/lookup/index.ts
index d1417de1903fd1538f15d232fd80d5a3ac978583..47f2f18883f942b8eed98bbf90a4ebd569d5e9c3 100644
--- a/lib/workers/repository/process/lookup/index.ts
+++ b/lib/workers/repository/process/lookup/index.ts
@@ -64,7 +64,7 @@ export async function lookupUpdates(
       res.skipReason = SkipReason.InvalidConfig;
       return res;
     }
-    const isValid = currentValue && versioning.isValid(currentValue);
+    const isValid = is.string(currentValue) && versioning.isValid(currentValue);
     if (unconstrainedValue || isValid) {
       if (
         !updatePinnedDependencies &&