diff --git a/node/src/integration-test/kotlin/net/corda/test/node/NodeStatePersistenceTests.kt b/node/src/integration-test/kotlin/net/corda/test/node/NodeStatePersistenceTests.kt
index 5b4cd1276a..9a71e5c60f 100644
--- a/node/src/integration-test/kotlin/net/corda/test/node/NodeStatePersistenceTests.kt
+++ b/node/src/integration-test/kotlin/net/corda/test/node/NodeStatePersistenceTests.kt
@@ -25,17 +25,23 @@ import net.corda.testing.chooseIdentity
 import net.corda.testing.driver.DriverDSLExposedInterface
 import net.corda.testing.driver.NodeHandle
 import net.corda.testing.driver.driver
+import org.junit.Assume
 import org.junit.Test
 import java.lang.management.ManagementFactory
 import javax.persistence.Column
 import javax.persistence.Entity
 import javax.persistence.Table
 import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
 
 class NodeStatePersistenceTests {
 
     @Test
     fun `persistent state survives node restart`() {
+        // Temporary disable this test when executed on Windows. It is known to be sporadically failing.
+        // More investigation is needed to establish why.
+        Assume.assumeFalse(System.getProperty("os.name").toLowerCase().startsWith("win"))
+
         val user = User("mark", "dadada", setOf(FlowPermissions.startFlowPermission<SendMessageFlow>()))
         val message = Message("Hello world!")
         driver(isDebug = true, startNodesInProcess = isQuasarAgentSpecified()) {
@@ -55,7 +61,9 @@ class NodeStatePersistenceTests {
             ensureAcquainted(notaryNodeHandle, nodeHandle)
             nodeHandle.rpcClientToNode().start(user.username, user.password).use {
                 val page = it.proxy.vaultQuery(MessageState::class.java)
-                val retrievedMessage = page.states.singleOrNull()?.state?.data?.message
+                val stateAndRef = page.states.singleOrNull()
+                assertNotNull(stateAndRef)
+                val retrievedMessage = stateAndRef!!.state.data.message
                 assertEquals(message, retrievedMessage)
             }
         }