diff --git a/AsbCloudDb/EFExtensions.cs b/AsbCloudDb/EFExtensions.cs
index 4b8361e7..8829462a 100644
--- a/AsbCloudDb/EFExtensions.cs
+++ b/AsbCloudDb/EFExtensions.cs
@@ -223,6 +223,7 @@ namespace AsbCloudDb
         private static string FormatValue(object? v)
         => v switch
         {
+            null => "NULL",
             string vStr => $"'{EscapeCurlyBraces(vStr)}'",
             DateTime vDate => $"'{FormatDateValue(vDate)}'",
             DateTimeOffset vDate => $"'{FormatDateValue(vDate.UtcDateTime)}'",