diff --git a/node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt b/node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt
index 34cd6bd068..ad4e7c7acb 100644
--- a/node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt
+++ b/node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt
@@ -76,6 +76,14 @@ abstract class AbstractNode(open val configuration: NodeConfiguration, val netwo
     companion object {
         val PRIVATE_KEY_FILE_NAME = "identity-private-key"
         val PUBLIC_IDENTITY_FILE_NAME = "identity-public"
+
+        val defaultFlowWhiteList: Map<Class<out FlowLogic<*>>, Set<Class<*>>> = mapOf(
+                CashFlow::class.java to setOf(
+                        CashCommand.IssueCash::class.java,
+                        CashCommand.PayCash::class.java,
+                        CashCommand.ExitCash::class.java
+                )
+        )
     }
 
     // TODO: Persist this, as well as whether the node is registered.
@@ -309,14 +317,6 @@ abstract class AbstractNode(open val configuration: NodeConfiguration, val netwo
         }
     }
 
-    private val defaultFlowWhiteList: Map<Class<out FlowLogic<*>>, Set<Class<*>>> = mapOf(
-            CashFlow::class.java to setOf(
-                    CashCommand.IssueCash::class.java,
-                    CashCommand.PayCash::class.java,
-                    CashCommand.ExitCash::class.java
-            )
-    )
-
     private fun initialiseFlowLogicFactory(): FlowLogicRefFactory {
         val flowWhitelist = HashMap<String, Set<String>>()
 
diff --git a/node/src/main/kotlin/net/corda/node/services/messaging/RPCStructures.kt b/node/src/main/kotlin/net/corda/node/services/messaging/RPCStructures.kt
index 542696ffa3..bbe9285964 100644
--- a/node/src/main/kotlin/net/corda/node/services/messaging/RPCStructures.kt
+++ b/node/src/main/kotlin/net/corda/node/services/messaging/RPCStructures.kt
@@ -26,6 +26,7 @@ import net.corda.core.serialization.*
 import net.corda.core.transactions.SignedTransaction
 import net.corda.core.transactions.WireTransaction
 import net.corda.flows.CashFlowResult
+import net.corda.node.internal.AbstractNode
 import net.corda.node.services.User
 import net.i2p.crypto.eddsa.EdDSAPrivateKey
 import net.i2p.crypto.eddsa.EdDSAPublicKey
@@ -106,6 +107,17 @@ open class RPCException(msg: String, cause: Throwable?) : RuntimeException(msg,
     class DeadlineExceeded(rpcName: String) : RPCException("Deadline exceeded on call to $rpcName")
 }
 
+object ClassSerializer : Serializer<Class<*>>() {
+    override fun read(kryo: Kryo, input: Input, type: Class<Class<*>>): Class<*> {
+        val className = input.readString()
+        return Class.forName(className)
+    }
+
+    override fun write(kryo: Kryo, output: Output, clazz: Class<*>) {
+        output.writeString(clazz.name)
+    }
+}
+
 class PermissionException(msg: String) : RuntimeException(msg)
 
 // The Kryo used for the RPC wire protocol. Every type in the wire protocol is listed here explicitly.
@@ -133,7 +145,7 @@ private class RPCKryo(observableSerializer: Serializer<Observable<Any>>? = null)
         register(SerializedBytes::class.java, SerializedBytesSerializer)
         register(Party::class.java)
         register(Array<Any>(0,{}).javaClass)
-        register(Class::class.java)
+        register(Class::class.java, ClassSerializer)
 
         ImmutableListSerializer.registerSerializers(this)
         ImmutableSetSerializer.registerSerializers(this)
@@ -224,6 +236,11 @@ private class RPCKryo(observableSerializer: Serializer<Observable<Any>>? = null)
         register(FlowHandle::class.java)
         register(KryoException::class.java)
         register(StringBuffer::class.java)
+        for ((_flow, argumentTypes) in AbstractNode.defaultFlowWhiteList) {
+            for (type in argumentTypes) {
+                register(type)
+            }
+        }
         pluginRegistries.forEach { it.registerRPCKryoTypes(this) }
     }