diff --git a/src/Api/Models/Request/Organizations/OrganizationSponsorshipCreateRequestModel.cs b/src/Api/Models/Request/Organizations/OrganizationSponsorshipCreateRequestModel.cs
index 3b2e873385..d3f03a7ddc 100644
--- a/src/Api/Models/Request/Organizations/OrganizationSponsorshipCreateRequestModel.cs
+++ b/src/Api/Models/Request/Organizations/OrganizationSponsorshipCreateRequestModel.cs
@@ -23,5 +23,7 @@ public class OrganizationSponsorshipCreateRequestModel
     /// <remarks>Left empty when creating a sponsorship for the authenticated user.</remarks>
     public Guid? SponsoringUserId { get; set; }
 
+    [EncryptedString]
+    [EncryptedStringLength(512)]
     public string Notes { get; set; }
 }