diff --git a/EnvelopeGenerator.Application/Common/Interfaces/Services/Notification/EnvelopeNotificationBase.cs b/EnvelopeGenerator.Application/Common/Interfaces/Services/Notification/EnvelopeNotificationBase.cs
index 1d22fd01..f43df0cc 100644
--- a/EnvelopeGenerator.Application/Common/Interfaces/Services/Notification/EnvelopeNotificationBase.cs
+++ b/EnvelopeGenerator.Application/Common/Interfaces/Services/Notification/EnvelopeNotificationBase.cs
@@ -15,5 +15,5 @@ public abstract record EnvelopeNotificationBase
     /// <summary>
     /// 
     /// </summary>
-    public List<(string FileName, byte[] Content)>? Attachments { get; init; }
+    public IReadOnlyList<(string FileName, byte[] Content)>? Attachments { get; init; }
 }
diff --git a/EnvelopeGenerator.Application/PdfSigning/FinalizeEnvelopeCommand.cs b/EnvelopeGenerator.Application/PdfSigning/FinalizeEnvelopeCommand.cs
index 2a7aff81..737320a8 100644
--- a/EnvelopeGenerator.Application/PdfSigning/FinalizeEnvelopeCommand.cs
+++ b/EnvelopeGenerator.Application/PdfSigning/FinalizeEnvelopeCommand.cs
@@ -98,9 +98,7 @@ public class FinalizeEnvelopeCommandHandler(IRepository<Envelope> Repo, ISender
             {
                 DocumentTitle = envelope.Title,
                 NameReceiver = er.Name,
-                Attachments = [
-                    ($"unterzeichnetes-dokument.pdf", doc)
-                    ]
+                Attachments = [($"unterzeichnetes-dokument.pdf", doc)]
             }, cancel);
         }