diff --git a/node/src/main/kotlin/net/corda/node/serialization/kryo/DefaultKryoCustomizer.kt b/node/src/main/kotlin/net/corda/node/serialization/kryo/DefaultKryoCustomizer.kt
index ac1c2ec674..0c6d50f903 100644
--- a/node/src/main/kotlin/net/corda/node/serialization/kryo/DefaultKryoCustomizer.kt
+++ b/node/src/main/kotlin/net/corda/node/serialization/kryo/DefaultKryoCustomizer.kt
@@ -42,8 +42,8 @@ import org.objenesis.instantiator.ObjectInstantiator
 import org.objenesis.strategy.InstantiatorStrategy
 import org.objenesis.strategy.StdInstantiatorStrategy
 import org.slf4j.Logger
-import sun.security.ec.ECPublicKeyImpl
-import sun.security.provider.certpath.X509CertPath
+//import sun.security.ec.ECPublicKeyImpl
+//import sun.security.provider.certpath.X509CertPath
 import java.io.BufferedInputStream
 import java.io.ByteArrayOutputStream
 import java.io.FileInputStream
@@ -97,7 +97,7 @@ object DefaultKryoCustomizer {
             register(BufferedInputStream::class.java, InputStreamSerializer)
             register(Class.forName("sun.net.www.protocol.jar.JarURLConnection\$JarURLInputStream"), InputStreamSerializer)
             noReferencesWithin<WireTransaction>()
-            register(ECPublicKeyImpl::class.java, publicKeySerializer)
+//            register(ECPublicKeyImpl::class.java, publicKeySerializer)
             register(EdDSAPublicKey::class.java, publicKeySerializer)
             register(EdDSAPrivateKey::class.java, PrivateKeySerializer)
             register(CompositeKey::class.java, publicKeySerializer)  // Using a custom serializer for compactness
@@ -109,7 +109,7 @@ object DefaultKryoCustomizer {
             register(Class::class.java, ClassSerializer)
             register(FileInputStream::class.java, InputStreamSerializer)
             register(CertPath::class.java, CertPathSerializer)
-            register(X509CertPath::class.java, CertPathSerializer)
+//            register(X509CertPath::class.java, CertPathSerializer)
             register(BCECPrivateKey::class.java, PrivateKeySerializer)
             register(BCECPublicKey::class.java, publicKeySerializer)
             register(BCRSAPrivateCrtKey::class.java, PrivateKeySerializer)
diff --git a/serialization/src/main/kotlin/net/corda/serialization/internal/AllButBlacklisted.kt b/serialization/src/main/kotlin/net/corda/serialization/internal/AllButBlacklisted.kt
index 8493821fb4..3ffc788b51 100644
--- a/serialization/src/main/kotlin/net/corda/serialization/internal/AllButBlacklisted.kt
+++ b/serialization/src/main/kotlin/net/corda/serialization/internal/AllButBlacklisted.kt
@@ -2,8 +2,8 @@ package net.corda.serialization.internal
 
 import net.corda.core.DeleteForDJVM
 import net.corda.core.serialization.ClassWhitelist
-import sun.misc.Unsafe
-import sun.security.util.Password
+//import sun.misc.Unsafe
+//import sun.security.util.Password
 import java.io.*
 import java.lang.invoke.*
 import java.lang.reflect.AccessibleObject
@@ -50,7 +50,7 @@ object AllButBlacklisted : ClassWhitelist {
             ClassLoader::class.java.name,
             Handler::class.java.name, // MemoryHandler, StreamHandler
             Runtime::class.java.name,
-            Unsafe::class.java.name,
+//            Unsafe::class.java.name,
             ZipFile::class.java.name,
             Provider::class.java.name,
             SecurityManager::class.java.name,
@@ -62,7 +62,7 @@ object AllButBlacklisted : ClassWhitelist {
 
             // java.security.
             KeyStore::class.java.name,
-            Password::class.java.name,
+//            Password::class.java.name,
             AccessController::class.java.name,
             Permission::class.java.name,
 
diff --git a/serialization/src/main/kotlin/net/corda/serialization/internal/DefaultWhitelist.kt b/serialization/src/main/kotlin/net/corda/serialization/internal/DefaultWhitelist.kt
index 1f4db775c4..b78314eff9 100644
--- a/serialization/src/main/kotlin/net/corda/serialization/internal/DefaultWhitelist.kt
+++ b/serialization/src/main/kotlin/net/corda/serialization/internal/DefaultWhitelist.kt
@@ -5,7 +5,7 @@ import net.corda.core.utilities.NetworkHostAndPort
 import org.apache.activemq.artemis.api.core.SimpleString
 import rx.Notification
 import rx.exceptions.OnErrorNotImplementedException
-import sun.security.x509.X509CertImpl
+//import sun.security.x509.X509CertImpl
 import java.security.cert.CRLReason
 import java.util.*
 
@@ -62,7 +62,7 @@ object DefaultWhitelist : SerializationWhitelist {
                     StackTraceElement::class.java,
 
                     // Implementation of X509Certificate.
-                    X509CertImpl::class.java,
+//                    X509CertImpl::class.java,
                     CRLReason::class.java
             )
 }