diff --git a/node/src/main/kotlin/net/corda/node/internal/FlowSafeSubject.kt b/node/src/main/kotlin/net/corda/node/internal/FlowSafeSubject.kt
index 4570c8f653..ee406dbaf6 100644
--- a/node/src/main/kotlin/net/corda/node/internal/FlowSafeSubject.kt
+++ b/node/src/main/kotlin/net/corda/node/internal/FlowSafeSubject.kt
@@ -40,9 +40,9 @@ class FlowSafeSubject<T, R>(private val actual: Subject<T, R>) : Observer<T> by
 /**
  * The [PreventSubscriptionsSubject] is used to prevent any subscriptions to its underlying [Subject].
  */
-class PreventSubscriptionsSubject<T, R>(private val actual: Subject<T, R>, errorAction: () -> Unit) : Observer<T> by actual,
+class PreventSubscriptionsSubject<T, R>(private val actual: Subject<T, R>, errorAction: () -> Exception) : Observer<T> by actual,
     Subject<T, R>(OnSubscribe<R> { _ ->
-        errorAction()
+        throw errorAction()
     }) {
 
     override fun hasObservers(): Boolean {
diff --git a/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt b/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt
index ac0b5e7cb2..8f33b3f129 100644
--- a/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt
+++ b/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt
@@ -226,7 +226,7 @@ class NodeVaultService(
                                 "- aborting the flow "
                     )
 
-                    throw FlowException(
+                    FlowException(
                         "Flow ${it.logic::class.java.name} tried to subscribe an Rx.Observer to VaultService.rawUpdates " +
                                 "- Rx.Observables should only be subscribed outside the context of a flow " +
                                 "- the subscription did not succeed "