diff --git a/SabreTools.Library/DatItems/Media.cs b/SabreTools.Library/DatItems/Media.cs
index 3857a289..de5fdc0a 100644
--- a/SabreTools.Library/DatItems/Media.cs
+++ b/SabreTools.Library/DatItems/Media.cs
@@ -70,7 +70,7 @@ namespace SabreTools.Library.DatItems
         public string SpamSum
         {
             get { return _spamsum.IsNullOrEmpty() ? null : Encoding.UTF8.GetString(_spamsum); }
-            set { _spamsum = Encoding.UTF8.GetBytes(value); }
+            set { _spamsum = Encoding.UTF8.GetBytes(value ?? string.Empty); }
         }
 
         #endregion
diff --git a/SabreTools.Library/DatItems/Rom.cs b/SabreTools.Library/DatItems/Rom.cs
index f7f2fb80..eed2f3a4 100644
--- a/SabreTools.Library/DatItems/Rom.cs
+++ b/SabreTools.Library/DatItems/Rom.cs
@@ -135,7 +135,7 @@ namespace SabreTools.Library.DatItems
         public string SpamSum
         {
             get { return _spamsum.IsNullOrEmpty() ? null : Encoding.UTF8.GetString(_spamsum); }
-            set { _spamsum = Encoding.UTF8.GetBytes(value); }
+            set { _spamsum = Encoding.UTF8.GetBytes(value ?? string.Empty); }
         }
 
         /// <summary>