diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index f03ffc506593..c96a4f6501e9 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -17416,7 +17416,7 @@ QuotaClient::PerformIdleMaintenanceOnDatabaseInternal(
     nsCOMPtr<mozIStorageConnection> mConnection;
 
   public:
-    AutoClose(mozIStorageConnection* aConnection)
+    explicit AutoClose(mozIStorageConnection* aConnection)
       : mConnection(aConnection)
     {
       MOZ_ASSERT(aConnection);