diff --git a/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/MapSerializer.kt b/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/MapSerializer.kt
index 2853ba47ee..eb45430453 100644
--- a/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/MapSerializer.kt
+++ b/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/MapSerializer.kt
@@ -18,18 +18,23 @@ class MapSerializer(val declaredType: ParameterizedType, factory: SerializerFact
     override val typeDescriptor = "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}"
 
     companion object {
-        private val supportedTypes: Map<Class<out Any>, (Map<*, *>) -> Map<*, *>> = mapOf(
+        private val supportedTypes: Map<Class<out Any?>, (Map<*, *>) -> Map<*, *>> = mapOf(
+                // Interfaces
                 Map::class.java to { map -> map },
                 SortedMap::class.java to { map -> TreeMap(map) },
                 NavigableMap::class.java to { map -> TreeMap(map) },
+                // Sub types
                 Dictionary::class.java to { map -> Hashtable(map) },
-                // concrete types for user convienience
-                HashMap::class.java to { map -> LinkedHashMap(map) },
+                AbstractMap::class.java to { map -> LinkedHashMap(map) },
+                // concrete types
                 LinkedHashMap::class.java to { map -> LinkedHashMap(map) },
                 TreeMap::class.java to { map -> TreeMap(map) },
-                Hashtable::class.java to { map -> Hashtable(map) }
+                Hashtable::class.java to { map -> Hashtable(map) },
+                WeakHashMap::class.java to { map -> WeakHashMap(map) }
+                // Explicitly disallowed
+                //  - HashMap::class.java
+                //  - EnumMap::class.java
         )
-
         private fun findConcreteType(clazz: Class<*>): (Map<*, *>) -> Map<*, *> {
             return supportedTypes[clazz] ?: throw NotSerializableException("Unsupported map type $clazz.")
         }
diff --git a/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationHelper.kt b/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationHelper.kt
index a8c15461ca..57efe40cab 100644
--- a/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationHelper.kt
+++ b/node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationHelper.kt
@@ -35,6 +35,7 @@ internal fun constructorForDeserialization(type: Type): KFunction<Any>? {
         val kotlinConstructors = clazz.kotlin.constructors
         val hasDefault = kotlinConstructors.any { it.parameters.isEmpty() }
         for (kotlinConstructor in kotlinConstructors) {
+            println (kotlinConstructor)
             if (preferredCandidate == null && kotlinConstructors.size == 1 && !hasDefault) {
                 preferredCandidate = kotlinConstructor
             } else if (preferredCandidate == null && kotlinConstructors.size == 2 && hasDefault && kotlinConstructor.parameters.isNotEmpty()) {
@@ -44,6 +45,7 @@ internal fun constructorForDeserialization(type: Type): KFunction<Any>? {
                     throw NotSerializableException("More than one constructor for $clazz is annotated with @CordaConstructor.")
                 }
                 preferredCandidate = kotlinConstructor
+                println ("  -> $preferredCandidate")
             }
         }
         return preferredCandidate ?: throw NotSerializableException("No constructor for deserialization found for $clazz.")
diff --git a/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/DeserializeMapTests.kt b/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/DeserializeMapTests.kt
index da16929ccb..3c9a615baa 100644
--- a/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/DeserializeMapTests.kt
+++ b/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/DeserializeMapTests.kt
@@ -5,7 +5,8 @@ import java.util.*
 import org.apache.qpid.proton.codec.Data
 
 class DeserializeCollectionTests {
-class TestSerializationOutput(
+
+    class TestSerializationOutput(
             private val verbose: Boolean,
             serializerFactory: SerializerFactory = SerializerFactory()) : SerializationOutput(serializerFactory) {
 
@@ -32,6 +33,23 @@ class TestSerializationOutput(
         DeserializationInput(sf).deserialize(serialisedBytes)
     }
 
+    @Test
+    fun abstractMapFromMapOf() {
+        data class C(val c: AbstractMap<String, Int>)
+        val c = C (mapOf("A" to 1, "B" to 2) as AbstractMap)
+
+        val serialisedBytes = TestSerializationOutput(VERBOSE, sf).serialize(c)
+        DeserializationInput(sf).deserialize(serialisedBytes)
+    }
+
+    @Test
+    fun abstractMapFromTreeMap() {
+        data class C(val c: AbstractMap<String, Int>)
+        val c = C (TreeMap(mapOf("A" to 1, "B" to 2)))
+
+        val serialisedBytes = TestSerializationOutput(VERBOSE, sf).serialize(c)
+        DeserializationInput(sf).deserialize(serialisedBytes)
+    }
     @Test
     fun sortedMapTest() {
         data class C(val c: SortedMap<String, Int>)
@@ -40,6 +58,15 @@ class TestSerializationOutput(
         DeserializationInput(sf).deserialize(serialisedBytes)
     }
 
+    @Test
+    fun navigableMapTest() {
+        data class C(val c: NavigableMap<String, Int>)
+        val c = C(TreeMap (mapOf("A" to 1, "B" to 2)).descendingMap())
+
+        val serialisedBytes = TestSerializationOutput(VERBOSE, sf).serialize(c)
+        DeserializationInput(sf).deserialize(serialisedBytes)
+    }
+
     @Test
     fun dictionaryTest() {
         data class C(val c: Dictionary<String, Int>)
@@ -51,17 +78,8 @@ class TestSerializationOutput(
         DeserializationInput(sf).deserialize(serialisedBytes)
     }
 
-    @Test
-    fun navigableMapTest() {
-        data class C(val c: NavigableMap<String, Int>)
-        val c = C(TreeMap (mapOf("A" to 1, "B" to 3)).descendingMap())
-
-        val serialisedBytes = TestSerializationOutput(VERBOSE, sf).serialize(c)
-        DeserializationInput(sf).deserialize(serialisedBytes)
-    }
-
     @Test(expected=java.lang.IllegalArgumentException::class)
-    fun HashMapTest() {
+    fun hashMapTest() {
         data class C(val c : HashMap<String, Int>)
         val c = C (HashMap (mapOf("A" to 1, "B" to 2)))
 
@@ -69,6 +87,15 @@ class TestSerializationOutput(
         TestSerializationOutput(VERBOSE, sf).serialize(c)
     }
 
+    @Test
+    fun weakHashMapTest() {
+        data class C(val c : WeakHashMap<String, Int>)
+        val c = C (WeakHashMap (mapOf("A" to 1, "B" to 2)))
+
+        val serialisedBytes = TestSerializationOutput(VERBOSE, sf).serialize(c)
+        DeserializationInput(sf).deserialize(serialisedBytes)
+    }
+
     @Test
     fun concreteTreeMapTest() {
         data class C(val c: TreeMap<String, Int>)
@@ -84,10 +111,6 @@ class TestSerializationOutput(
         val c = C (LinkedHashMap (mapOf("A" to 1, "B" to 2)))
 
         val serialisedBytes = TestSerializationOutput(VERBOSE, sf).serialize(c)
-        val deserializedObj = DeserializationInput(sf).deserialize(serialisedBytes)
+        DeserializationInput(sf).deserialize(serialisedBytes)
     }
-
-
-
-
 }
diff --git a/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationOutputTests.kt b/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationOutputTests.kt
index 70a68e8cce..013fbaddc8 100644
--- a/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationOutputTests.kt
+++ b/node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializationOutputTests.kt
@@ -356,7 +356,7 @@ class SerializationOutputTests {
         serdes(obj)
     }
 
-    @Test(expected = NotSerializableException::class)
+    @Test
     fun `test TreeMap property`() {
         val obj = TreeMapWrapper(TreeMap<Int, Foo>())
         obj.tree[456] = Foo("Fred", 123)