diff --git a/app/MindWork AI Studio/Provider/OpenAI/ResponsesDeltaStreamLine.cs b/app/MindWork AI Studio/Provider/OpenAI/ResponsesDeltaStreamLine.cs
index 98ea7eb2..0c1767d0 100644
--- a/app/MindWork AI Studio/Provider/OpenAI/ResponsesDeltaStreamLine.cs	
+++ b/app/MindWork AI Studio/Provider/OpenAI/ResponsesDeltaStreamLine.cs	
@@ -7,7 +7,7 @@ namespace AIStudio.Provider.OpenAI;
 /// <param name="Delta">The delta content of the response.</param>
 public record ResponsesDeltaStreamLine(
     string Type,
-    string Delta) : IResponseStreamLine
+    string? Delta) : IResponseStreamLine
 {
     #region Implementation of IResponseStreamLine
 
@@ -15,7 +15,7 @@ public record ResponsesDeltaStreamLine(
     public bool ContainsContent() => this.Delta is not null;
 
     /// <inheritdoc />
-    public ContentStreamChunk GetContent() => new(this.Delta, this.GetSources());
+    public ContentStreamChunk GetContent() => new(this.Delta ?? string.Empty, this.GetSources());
 
     //
     // Please note that there are multiple options where LLM providers might stream sources:
@@ -36,4 +36,4 @@ public record ResponsesDeltaStreamLine(
     public IList<ISource> GetSources() => [];
 
     #endregion
-}
+}
\ No newline at end of file