diff --git a/lib/src/kdbx_format.dart b/lib/src/kdbx_format.dart
index c028d9f..3dd4be4 100644
--- a/lib/src/kdbx_format.dart
+++ b/lib/src/kdbx_format.dart
@@ -505,7 +505,9 @@ class MergeContext implements OverwriteContext {
   }
 
   String debugSummary() {
-    return 'Changes: ${changes.length}, Deleted: ${deletedObjects.length}, Warnings: ${warnings.join(', ')}';
+    return 'Changes: ${changes.length}, '
+        'Deleted: ${deletedObjects.length}, '
+        'Warnings: ${warnings.isEmpty ? 'None' : warnings.join(', ')}';
   }
 
   @override