diff --git a/src/food-market.api/Background/OrgExportJob.cs b/src/food-market.api/Background/OrgExportJob.cs
index 9dc90e7..ebaca29 100644
--- a/src/food-market.api/Background/OrgExportJob.cs
+++ b/src/food-market.api/Background/OrgExportJob.cs
@@ -186,7 +186,7 @@ await using (var s = rEntry.Open())
     }
 
     private static async Task WriteCollection<T>(ZipArchive zip, string name,
-        IQueryable<T> q, JsonSerializerOptions opts, CancellationToken ct)
+        IQueryable<T> q, JsonSerializerOptions opts, CancellationToken ct) where T : class
     {
         var items = await q.AsNoTracking().ToListAsync(ct);
         await WriteJsonEntry(zip, name, items, opts, ct);