diff --git a/core/src/main/kotlin/com/r3corda/core/node/services/NetworkMapCache.kt b/core/src/main/kotlin/com/r3corda/core/node/services/NetworkMapCache.kt
index 997bada9a1..d909a8eb79 100644
--- a/core/src/main/kotlin/com/r3corda/core/node/services/NetworkMapCache.kt
+++ b/core/src/main/kotlin/com/r3corda/core/node/services/NetworkMapCache.kt
@@ -20,6 +20,9 @@ interface NetworkMapCache {
         val logger = LoggerFactory.getLogger(NetworkMapCache::class.java)
     }
 
+    enum class MapChangeType { Added, Removed }
+    data class MapChange(val node: NodeInfo, val type: MapChangeType )
+
     /** A list of nodes that advertise a network map service */
     val networkMapNodes: List<NodeInfo>
     /** A list of nodes that advertise a notary service */
@@ -28,10 +31,8 @@ interface NetworkMapCache {
     val ratesOracleNodes: List<NodeInfo>
     /** A list of all nodes the cache is aware of */
     val partyNodes: List<NodeInfo>
-    /** Observer for additions to the cache */
-    val added: Observable<NodeInfo>
-    /** Observer for removal from the cache */
-    val removed: Observable<NodeInfo>
+    /** Tracks changes to the network map cache */
+    val changed: Observable<MapChange>
 
     /**
      * A list of nodes that advertise a regulatory service. Identifying the correct regulator for a trade is outside
diff --git a/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt b/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt
index 1c958299a0..4b3cd105e7 100644
--- a/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt
+++ b/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt
@@ -27,6 +27,8 @@ import com.r3corda.node.services.events.NodeSchedulerService
 import com.r3corda.node.services.events.ScheduledActivityObserver
 import com.r3corda.node.services.identity.InMemoryIdentityService
 import com.r3corda.node.services.keys.E2ETestKeyManagementService
+import com.r3corda.core.node.services.NetworkMapCache
+import com.r3corda.core.node.services.NetworkMapCache.MapChangeType
 import com.r3corda.node.services.network.InMemoryNetworkMapCache
 import com.r3corda.node.services.network.InMemoryNetworkMapService
 import com.r3corda.node.services.network.NetworkMapService
@@ -309,8 +311,10 @@ abstract class AbstractNode(val dir: Path, val configuration: NodeConfiguration,
 
         services.networkMapCache.partyNodes.forEach { service.registerIdentity(it.identity) }
 
-        netMapCache.added.subscribe { node ->
-            service.registerIdentity(node.identity)
+        netMapCache.changed.subscribe { mapChange ->
+            if(mapChange.type == MapChangeType.Added) {
+                service.registerIdentity(mapChange.node.identity)
+            }
         }
 
         return service
diff --git a/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt b/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt
index b56cc68424..b023efbc69 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt
@@ -13,6 +13,8 @@ import com.r3corda.core.node.NodeInfo
 import com.r3corda.core.node.services.DEFAULT_SESSION_ID
 import com.r3corda.core.node.services.NetworkCacheError
 import com.r3corda.core.node.services.NetworkMapCache
+import com.r3corda.core.node.services.NetworkMapCache.MapChangeType
+import com.r3corda.core.node.services.NetworkMapCache.MapChange
 import com.r3corda.core.node.services.ServiceType
 import com.r3corda.core.random63BitValue
 import com.r3corda.core.serialization.SingletonSerializeAsToken
@@ -45,14 +47,9 @@ open class InMemoryNetworkMapCache(val netInternal: MessagingServiceInternal?) :
         get() = get(NodeInterestRates.Type)
     override val partyNodes: List<NodeInfo>
         get() = registeredNodes.map { it.value }
-    private val _added = PublishSubject.create<NodeInfo>()
-    private val _removed = PublishSubject.create<NodeInfo>()
-    override val added: Observable<NodeInfo>
-        get() = _added
-    override val removed: Observable<NodeInfo>
-        get() = _removed
+    private val _changed = PublishSubject.create<MapChange>()
+    override val changed: Observable<MapChange> = _changed
 
-    private var listener: (node: NodeInfo, added: Boolean) -> Unit? = { a, b -> Unit}
     private var registeredForPush = false
     protected var registeredNodes = Collections.synchronizedMap(HashMap<Party, NodeInfo>())
 
@@ -104,12 +101,12 @@ open class InMemoryNetworkMapCache(val netInternal: MessagingServiceInternal?) :
     override fun addNode(node: NodeInfo) {
         registeredNodes[node.identity] = node
         netInternal?.registerTrustedAddress(node.address)
-        _added.onNext(node)
+        _changed.onNext(MapChange(node, MapChangeType.Added))
     }
 
     override fun removeNode(node: NodeInfo) {
         registeredNodes.remove(node.identity)
-        _removed.onNext(node)
+        _changed.onNext(MapChange(node, MapChangeType.Removed))
     }
 
     /**
diff --git a/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt b/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt
index b652393804..ea31653359 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt
@@ -5,6 +5,7 @@ import com.r3corda.core.crypto.DummyPublicKey
 import com.r3corda.core.crypto.Party
 import com.r3corda.core.messaging.SingleMessageRecipient
 import com.r3corda.core.node.NodeInfo
+import com.r3corda.core.node.services.NetworkMapCache
 import rx.Observable
 import rx.subjects.PublishSubject
 
@@ -12,12 +13,7 @@ import rx.subjects.PublishSubject
  * Network map cache with no backing map service.
  */
 class MockNetworkMapCache() : InMemoryNetworkMapCache(null) {
-    private val _added = PublishSubject.create<NodeInfo>()
-    private val _removed = PublishSubject.create<NodeInfo>()
-    override val added: Observable<NodeInfo>
-        get() = _added
-    override val removed: Observable<NodeInfo>
-        get() = _removed
+    override val changed: Observable<NetworkMapCache.MapChange> = PublishSubject.create<NetworkMapCache.MapChange>()
 
     data class MockAddress(val id: String): SingleMessageRecipient