diff --git a/moor/lib/src/runtime/executor/helpers/engines.dart b/moor/lib/src/runtime/executor/helpers/engines.dart
index d8a95b47..5d0180f2 100644
--- a/moor/lib/src/runtime/executor/helpers/engines.dart
+++ b/moor/lib/src/runtime/executor/helpers/engines.dart
@@ -263,7 +263,6 @@ class DelegatedDatabase extends _BaseExecutor {
   SqlDialect get dialect => delegate.dialect;
 
   final Lock _openingLock = Lock();
-  bool _closed = false;
 
   /// Constructs a delegated database by providing the [delegate].
   DelegatedDatabase(this.delegate,