diff --git a/Src/Notion.Client/RestClient/RestClient.cs b/Src/Notion.Client/RestClient/RestClient.cs
index 3def9161..91428218 100644
--- a/Src/Notion.Client/RestClient/RestClient.cs
+++ b/Src/Notion.Client/RestClient/RestClient.cs
@@ -69,7 +69,7 @@ private static async Task<Exception> BuildException(HttpResponseMessage response
                 }
             }
 
-            return new NotionApiException(response.StatusCode, errorResponse?.ErrorCode, errorResponse.Message);
+            return new NotionApiException(response.StatusCode, errorResponse?.ErrorCode, errorResponse?.Message);
         }
 
         private async Task<HttpResponseMessage> SendAsync(