diff --git a/commons/src/test/java/org/archive/util/IdentityCacheableWrapper.java b/commons/src/test/java/org/archive/util/IdentityCacheableWrapper.java
index 60b0e4e7..a93eb6df 100644
--- a/commons/src/test/java/org/archive/util/IdentityCacheableWrapper.java
+++ b/commons/src/test/java/org/archive/util/IdentityCacheableWrapper.java
@@ -31,6 +31,9 @@ public class IdentityCacheableWrapper<K> implements IdentityCacheable {
     
     protected K wrapped; 
     
+    // For Kryo serialization
+    IdentityCacheableWrapper() { }
+
     public IdentityCacheableWrapper(String key, K wrapped) {
         super();
         this.wrapped = wrapped;