diff --git a/lib/src/kdbx_format.dart b/lib/src/kdbx_format.dart
index 3dd4be4..773bffd 100644
--- a/lib/src/kdbx_format.dart
+++ b/lib/src/kdbx_format.dart
@@ -512,7 +512,7 @@ class MergeContext implements OverwriteContext {
 
   @override
   String toString() {
-    return '$runtimeType{${debugSummary()}';
+    return '$runtimeType{${debugSummary()}}';
   }
 }