diff --git a/runtime/CoreClasses.cs b/runtime/CoreClasses.cs
index d8cefb0a..a6f8e1ff 100644
--- a/runtime/CoreClasses.cs
+++ b/runtime/CoreClasses.cs
@@ -42,6 +42,17 @@ namespace IKVM.Internal
 
 		internal static class java
 		{
+			internal static class io
+			{
+				internal static class Serializable
+				{
+					// NOTE we have a dummy static initializer, to make sure we don't get the beforeFieldInit attribute
+					// (we don't want the classes to be loaded prematurely, because they might not be available then)
+					static Serializable() { }
+					internal static readonly TypeWrapper Wrapper = ClassLoaderWrapper.LoadClassCritical("java.io.Serializable");
+				}
+			}
+
 			internal static class lang
 			{
 				internal static class Object
@@ -68,6 +79,14 @@ namespace IKVM.Internal
 					internal static readonly TypeWrapper Wrapper = ClassLoaderWrapper.LoadClassCritical("java.lang.Class");
 				}
 
+				internal static class Cloneable
+				{
+					// NOTE we have a dummy static initializer, to make sure we don't get the beforeFieldInit attribute
+					// (we don't want the classes to be loaded prematurely, because they might not be available then)
+					static Cloneable() {}
+					internal static readonly TypeWrapper Wrapper = ClassLoaderWrapper.LoadClassCritical("java.lang.Cloneable");
+				}
+
 				internal static class Throwable
 				{
 					// NOTE we have a dummy static initializer, to make sure we don't get the beforeFieldInit attribute
diff --git a/runtime/DotNetTypeWrapper.cs b/runtime/DotNetTypeWrapper.cs
index 2ccd6887..f2e3fb9f 100644
--- a/runtime/DotNetTypeWrapper.cs
+++ b/runtime/DotNetTypeWrapper.cs
@@ -2006,7 +2006,7 @@ namespace IKVM.Internal
 			internal override void EmitCall(CodeEmitter ilgen)
 			{
 				ilgen.Emit(OpCodes.Dup);
-				ilgen.Emit(OpCodes.Isinst, ClassLoaderWrapper.LoadClassCritical("java.lang.Cloneable").TypeAsBaseType);
+				ilgen.Emit(OpCodes.Isinst, CoreClasses.java.lang.Cloneable.Wrapper.TypeAsBaseType);
 				CodeEmitterLabel label1 = ilgen.DefineLabel();
 				ilgen.EmitBrtrue(label1);
 				CodeEmitterLabel label2 = ilgen.DefineLabel();
diff --git a/runtime/DynamicTypeWrapper.cs b/runtime/DynamicTypeWrapper.cs
index e70dc778..8e525b96 100644
--- a/runtime/DynamicTypeWrapper.cs
+++ b/runtime/DynamicTypeWrapper.cs
@@ -412,7 +412,7 @@ namespace IKVM.Internal
 		{
 			get
 			{
-				return this.IsSubTypeOf(ClassLoaderWrapper.LoadClassCritical("java.io.Serializable"));
+				return this.IsSubTypeOf(CoreClasses.java.io.Serializable.Wrapper);
 			}
 		}
 
@@ -4814,7 +4814,7 @@ namespace IKVM.Internal
 						// are public and so we can get away with replacing all other types with object.
 						argTypes[i + instance] = (args[i].IsPrimitive || args[i].IsGhost || args[i].IsNonPrimitiveValueType) ? args[i].TypeAsSignatureType : typeof(object);
 					}
-					argTypes[argTypes.Length - 1] = ClassLoaderWrapper.LoadClassCritical("ikvm.internal.CallerID").TypeAsSignatureType;
+					argTypes[argTypes.Length - 1] = CoreClasses.ikvm.@internal.CallerID.Wrapper.TypeAsSignatureType;
 					Type retType = (mw.ReturnType.IsPrimitive || mw.ReturnType.IsGhost || mw.ReturnType.IsNonPrimitiveValueType) ? mw.ReturnType.TypeAsSignatureType : typeof(object);
 					MethodBuilder mb = tb.DefineMethod("method", MethodAttributes.Public | MethodAttributes.Static, retType, argTypes);
 					AttributeHelper.HideFromJava(mb);
diff --git a/runtime/Serialization.cs b/runtime/Serialization.cs
index 4fff1663..1145d351 100644
--- a/runtime/Serialization.cs
+++ b/runtime/Serialization.cs
@@ -43,7 +43,6 @@ namespace IKVM.Internal
 		private static readonly CustomAttributeBuilder securityCriticalAttribute = new CustomAttributeBuilder(JVM.Import(typeof(SecurityCriticalAttribute)).GetConstructor(Type.EmptyTypes), new object[0]);
 		private static readonly TypeWrapper iserializable = ClassLoaderWrapper.GetWrapperFromType(JVM.Import(typeof(ISerializable)));
 		private static readonly TypeWrapper iobjectreference = ClassLoaderWrapper.GetWrapperFromType(JVM.Import(typeof(IObjectReference)));
-		private static readonly TypeWrapper serializable = ClassLoaderWrapper.LoadClassCritical("java.io.Serializable");
 		private static readonly TypeWrapper externalizable = ClassLoaderWrapper.LoadClassCritical("java.io.Externalizable");
 		private static readonly PermissionSet psetSerializationFormatter;
 
@@ -85,7 +84,7 @@ namespace IKVM.Internal
 			{
 				MarkSerializable(typeBuilder);
 			}
-			else if (wrapper.IsSubTypeOf(serializable) && IsSafeForAutomagicSerialization(wrapper))
+			else if (wrapper.IsSubTypeOf(CoreClasses.java.io.Serializable.Wrapper) && IsSafeForAutomagicSerialization(wrapper))
 			{
 				if (wrapper.IsSubTypeOf(externalizable))
 				{
@@ -95,7 +94,7 @@ namespace IKVM.Internal
 						MarkSerializable(typeBuilder);
 						ctor.Link();
 						serializationCtor = AddConstructor(typeBuilder, ctor, null, true);
-						if (!wrapper.BaseTypeWrapper.IsSubTypeOf(serializable))
+						if (!wrapper.BaseTypeWrapper.IsSubTypeOf(CoreClasses.java.io.Serializable.Wrapper))
 						{
 							AddGetObjectData(typeBuilder);
 						}
@@ -105,7 +104,7 @@ namespace IKVM.Internal
 						}
 					}
 				}
-				else if (wrapper.BaseTypeWrapper.IsSubTypeOf(serializable))
+				else if (wrapper.BaseTypeWrapper.IsSubTypeOf(CoreClasses.java.io.Serializable.Wrapper))
 				{
 					MethodBase baseCtor = wrapper.GetBaseSerializationConstructor();
 					if (baseCtor != null && (baseCtor.IsFamily || baseCtor.IsFamilyOrAssembly))
diff --git a/runtime/TypeWrapper.cs b/runtime/TypeWrapper.cs
index 18b55d7d..f41f6986 100644
--- a/runtime/TypeWrapper.cs
+++ b/runtime/TypeWrapper.cs
@@ -4809,8 +4809,8 @@ namespace IKVM.Internal
 				if(interfaces == null)
 				{
 					TypeWrapper[] tw = new TypeWrapper[2];
-					tw[0] = ClassLoaderWrapper.LoadClassCritical("java.lang.Cloneable");
-					tw[1] = ClassLoaderWrapper.LoadClassCritical("java.io.Serializable");
+					tw[0] = CoreClasses.java.lang.Cloneable.Wrapper;
+					tw[1] = CoreClasses.java.io.Serializable.Wrapper;
 					interfaces = tw;
 				}
 				return interfaces;