diff --git a/djvm/build.gradle b/djvm/build.gradle
index 7120ed8612..db88e8c4c5 100644
--- a/djvm/build.gradle
+++ b/djvm/build.gradle
@@ -9,7 +9,7 @@ description 'Corda deterministic JVM sandbox'
 
 ext {
     // Shaded version of ASM to avoid conflict with root project.
-    asm_version = '6.1.1'
+    asm_version = '6.2.1'
 }
 
 repositories {
diff --git a/djvm/src/main/kotlin/net/corda/djvm/rewiring/SandboxClassWriter.kt b/djvm/src/main/kotlin/net/corda/djvm/rewiring/SandboxClassWriter.kt
index 9eb74e3aee..e1a051d45c 100644
--- a/djvm/src/main/kotlin/net/corda/djvm/rewiring/SandboxClassWriter.kt
+++ b/djvm/src/main/kotlin/net/corda/djvm/rewiring/SandboxClassWriter.kt
@@ -22,15 +22,17 @@ import org.objectweb.asm.Type
  */
 open class SandboxClassWriter(
         classReader: ClassReader,
-        private val classLoader: ClassLoader,
+        private val cloader: ClassLoader,
         flags: Int = COMPUTE_FRAMES or COMPUTE_MAXS
 ) : ClassWriter(classReader, flags) {
 
+    override fun getClassLoader(): ClassLoader = cloader
+
     /**
      * Get the common super type of [type1] and [type2].
      */
     override fun getCommonSuperClass(type1: String, type2: String): String {
-        // Need to override [getCommonSuperClass] to ensure that the correct class loader is used.
+        // Need to override [getCommonSuperClass] to ensure that we use ClassLoader.loadClass().
         when {
             type1 == OBJECT_NAME -> return type1
             type2 == OBJECT_NAME -> return type2