diff --git a/src/Mscc.GenerativeAI/BaseModel.cs b/src/Mscc.GenerativeAI/BaseModel.cs
index 786ab093..f8c0a5da 100644
--- a/src/Mscc.GenerativeAI/BaseModel.cs
+++ b/src/Mscc.GenerativeAI/BaseModel.cs
@@ -29,6 +29,7 @@ public abstract class BaseModel : BaseLogger
 
         protected string _model;
         protected string? _apiKey;
+        protected string _apiVersion;
         protected string? _accessToken;
         protected string? _projectId;
         protected string _region = "us-central1";