diff --git a/testing/node-driver/src/integration-test/kotlin/net/corda/testing/driver/DriverTests.kt b/testing/node-driver/src/integration-test/kotlin/net/corda/testing/driver/DriverTests.kt
index f438548171..82cb45c8da 100644
--- a/testing/node-driver/src/integration-test/kotlin/net/corda/testing/driver/DriverTests.kt
+++ b/testing/node-driver/src/integration-test/kotlin/net/corda/testing/driver/DriverTests.kt
@@ -125,22 +125,22 @@ class DriverTests {
     }
 
     @Test
-    fun `driver rejects multiple nodes with the same name`() {
-
+    fun `driver rejects multiple nodes with the same name parallel`() {
         driver(DriverParameters(startNodesInProcess = true)) {
-
-            assertThatThrownBy { listOf(newNode(DUMMY_BANK_A_NAME)(), newNode(DUMMY_BANK_B_NAME)(), newNode(DUMMY_BANK_A_NAME)()).transpose().getOrThrow() }.isInstanceOf(IllegalArgumentException::class.java)
+            val nodes = listOf(newNode(DUMMY_BANK_A_NAME), newNode(DUMMY_BANK_B_NAME), newNode(DUMMY_BANK_A_NAME))
+            assertThatIllegalArgumentException().isThrownBy {
+                nodes.parallelStream().map { it.invoke() }.toList().transpose().getOrThrow()
+            }
         }
     }
 
     @Test
-    fun `driver rejects multiple nodes with the same name parallel`() {
-
-        driver(DriverParameters(startNodesInProcess = true)) {
-
-            val nodes = listOf(newNode(DUMMY_BANK_A_NAME), newNode(DUMMY_BANK_B_NAME), newNode(DUMMY_BANK_A_NAME))
-
-            assertThatThrownBy { nodes.parallelStream().map { it.invoke() }.toList().transpose().getOrThrow() }.isInstanceOf(IllegalArgumentException::class.java)
+    fun `driver rejects multiple nodes with the same organisation name`() {
+        driver(DriverParameters(startNodesInProcess = true, notarySpecs = emptyList())) {
+            newNode(CordaX500Name(commonName = "Notary", organisation = "R3CEV", locality = "New York", country = "US"))().getOrThrow()
+            assertThatIllegalArgumentException().isThrownBy {
+                newNode(CordaX500Name(commonName = "Regulator", organisation = "R3CEV", locality = "New York", country = "US"))().getOrThrow()
+            }
         }
     }
 
diff --git a/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/DriverDSLImpl.kt b/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/DriverDSLImpl.kt
index e255cdd499..0f95bdd1bc 100644
--- a/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/DriverDSLImpl.kt
+++ b/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/DriverDSLImpl.kt
@@ -103,7 +103,7 @@ class DriverDSLImpl(
     private val cordappPackages = extraCordappPackagesToScan + getCallerPackage()
     // Map from a nodes legal name to an observable emitting the number of nodes in its network map.
     private val countObservables = mutableMapOf<CordaX500Name, Observable<Int>>()
-    private val nodeNames = mutableSetOf<CordaX500Name>()
+    private val nodeOrgs = mutableSetOf<String>()
     /**
      * Future which completes when the network map is available, whether a local one or one from the CZ. This future acts
      * as a gate to prevent nodes from starting too early. The value of the future is a [LocalNetworkMap] object, which
@@ -194,11 +194,8 @@ class DriverDSLImpl(
         val p2pAddress = portAllocation.nextHostAndPort()
         // TODO: Derive name from the full picked name, don't just wrap the common name
         val name = providedName ?: CordaX500Name("${oneOf(names).organisation}-${p2pAddress.port}", "London", "GB")
-        synchronized(nodeNames) {
-            val wasANewNode = nodeNames.add(name)
-            if (!wasANewNode) {
-                throw IllegalArgumentException("Node with name $name is already started or starting.")
-            }
+        synchronized(nodeOrgs) {
+            require(nodeOrgs.add(name.organisation)) { "Node with organisation name ${name.organisation} is already started or starting" }
         }
         val registrationFuture = if (compatibilityZone?.rootCert != null) {
             // We don't need the network map to be available to be able to register the node
@@ -664,8 +661,8 @@ class DriverDSLImpl(
         val onNodeExit: () -> Unit = {
             localNetworkMap?.nodeInfosCopier?.removeConfig(baseDirectory)
             countObservables.remove(config.corda.myLegalName)
-            synchronized(nodeNames) {
-                nodeNames.remove(config.corda.myLegalName)
+            synchronized(nodeOrgs) {
+                nodeOrgs -= config.corda.myLegalName.organisation
             }
         }