diff --git a/db/db_impl.cc b/db/db_impl.cc
index 23f990c4105716a10adff9cafb85123c522ed2ac..0088ee56d9bb40f7379adec716aa4f8b4dbb7793 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -2912,6 +2912,7 @@ Status DBImpl::IngestExternalFile(
   status = ingestion_job.Prepare(external_files, super_version);
   CleanupSuperVersion(super_version);
   if (!status.ok()) {
+    InstrumentedMutexLock l(&mutex_);
     ReleaseFileNumberFromPendingOutputs(pending_output_elem);
     return status;
   }