diff --git a/gnu/bytecode/ParameterizedType.java b/gnu/bytecode/ParameterizedType.java
index b9d35945d..5d4adc0f4 100644
--- a/gnu/bytecode/ParameterizedType.java
+++ b/gnu/bytecode/ParameterizedType.java
@@ -2,8 +2,9 @@
 // This is free software;  for terms and warranty disclaimer see ./COPYING.
 
 package gnu.bytecode;
+import java.io.*;
 
-public class ParameterizedType extends ObjectType
+public class ParameterizedType extends ObjectType implements Externalizable
 {
     ClassType rawType;
     Type[] typeArgumentTypes;
@@ -146,4 +147,27 @@ public class ParameterizedType extends ObjectType
         this.rawType = rawType;
         this.typeArgumentTypes = typeArgumentTypes;
     }
+    public static final ParameterizedType make(ClassType rawType,
+                                               Type[] typeArgumentTypes,
+                                               char[] typeArgumentBounds) {
+        ParameterizedType ptype =
+            new ParameterizedType(rawType, typeArgumentTypes);
+        ptype.typeArgumentBounds = typeArgumentBounds;
+        return ptype;
+    }
+
+    public void writeExternal(ObjectOutput out) throws IOException
+    {
+        out.writeObject(rawType);
+        out.writeObject(typeArgumentTypes);
+        out.writeObject(typeArgumentBounds);
+    }
+
+    public void readExternal(ObjectInput in)
+        throws IOException, ClassNotFoundException
+    {
+        rawType = (ClassType) in.readObject();
+        typeArgumentTypes = (Type[]) in.readObject();
+        typeArgumentBounds = (char[]) in.readObject();
+    }
 }