diff --git a/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs b/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs
index 693230b..80b088a 100644
--- a/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs
+++ b/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs
@@ -2,7 +2,7 @@ using System.Globalization;
 
 namespace Upsilon.BaseTypes.Number
 {
-    internal class ScriptNumberDouble : ScriptNumber
+    public class ScriptNumberDouble : ScriptNumber
     {
         public double Value { get; }
         protected internal override bool IsFloat { get; } = true;
diff --git a/Upsilon/BaseTypes/TypeContainer.cs b/Upsilon/BaseTypes/TypeContainer.cs
index 3eca1aa..b458992 100644
--- a/Upsilon/BaseTypes/TypeContainer.cs
+++ b/Upsilon/BaseTypes/TypeContainer.cs
@@ -6,7 +6,7 @@ namespace Upsilon.BaseTypes
 {
     public class TypeContainer
     {
-        public Type Type { get; }
+        public Type Type { get; protected set; }
         public virtual string UserData { get; }
 
         protected TypeContainer(Type t)
@@ -77,6 +77,18 @@ namespace Upsilon.BaseTypes
         }
     }
 
+    internal class IgnoredUserDataTypeContainer : TypeContainer
+    {
+        public IgnoredUserDataTypeContainer() : base(BaseTypes.Type.Unknown)
+        {
+            Type = Type.UserData;
+        }
+
+        public IgnoredUserDataTypeContainer(string userData) : base(userData)
+        {
+        }
+    }
+
     public class UndefinedUserDataTypeContainer : TypeContainer
     {
         private System.Type RealType { get; set; }
diff --git a/Upsilon/BaseTypes/UserData/GenericUserData.cs b/Upsilon/BaseTypes/UserData/GenericUserData.cs
index 70e79de..d39bfbc 100644
--- a/Upsilon/BaseTypes/UserData/GenericUserData.cs
+++ b/Upsilon/BaseTypes/UserData/GenericUserData.cs
@@ -10,16 +10,7 @@ namespace Upsilon.BaseTypes.UserData
             Value = obj;
             _typeInfo = UserDataTypeHandler.GetTypeInfo(obj.GetType());
         }
-        public override TypeContainer Type
-        {
-            get
-            {
-                var typeData = _typeInfo.BoundTypeName;
-                if (typeData != null)
-                    return new TypeContainer(typeData);
-                return BaseTypes.Type.Unknown;
-            }
-        }
+        public override TypeContainer Type { get; } = new IgnoredUserDataTypeContainer();
 
         private object Value { get; }
         private readonly UserDataType _typeInfo;
diff --git a/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs b/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs
index 71945a6..9f7b5d3 100644
--- a/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs
@@ -14,6 +14,7 @@ namespace Upsilon.BaseTypes.UserData
         Subtraction,
         Multiplication,
         Division,
+        Modulo
     }
 
     public class UserDataTypeOperators
@@ -64,6 +65,9 @@ namespace Upsilon.BaseTypes.UserData
                     case "op_Division":
                         LoadMethod(OperatorType.Division, methodInfo);
                         break;
+                    case "op_Modulus":
+                        LoadMethod(OperatorType.Modulo, methodInfo);
+                        break;
                 }
             }
         }
diff --git a/Upsilon/BoundTypes/BoundTypeHandler.cs b/Upsilon/BoundTypes/BoundTypeHandler.cs
index f8b4759..3a21134 100644
--- a/Upsilon/BoundTypes/BoundTypeHandler.cs
+++ b/Upsilon/BoundTypes/BoundTypeHandler.cs
@@ -43,7 +43,8 @@ namespace Upsilon.BoundTypes
 
         public static string GetTypeName(System.Type type)
         {
-            return TypeDefinitions.FirstOrDefault(x => x.Value.ValidInternalTypes.Contains(type)).Key;
+            return TypeDefinitions.FirstOrDefault(x =>
+                x.Value.ValidInternalTypes.Any(validType => validType.IsAssignableFrom(type))).Key;
         }
 
         public static void LoadUserDataTypeDefinition(UserDataBoundTypeDefinition def)
diff --git a/Upsilon/Evaluator/Evaluator.cs b/Upsilon/Evaluator/Evaluator.cs
index 1fbb9fd..d8de77b 100644
--- a/Upsilon/Evaluator/Evaluator.cs
+++ b/Upsilon/Evaluator/Evaluator.cs
@@ -352,6 +352,13 @@ namespace Upsilon.Evaluator
                     {
                         return ((ScriptNumber)left) % ((ScriptNumber)right);
                     }
+                    else if (left.Type == Type.UserData)
+                    {
+                        var ud = (GenericUserData) left;
+                        var (type, failed) = ud.BinaryOperator(left, OperatorType.Modulo, right);
+                        if (failed) goto default;
+                        return type;
+                    }
                     goto default;
                 case BoundBinaryOperator.OperatorKind.Equality:
                     return new ScriptBoolean(left.Equals(right));