diff --git a/constants.properties b/constants.properties
index 3c240a7676..4f0c0e1db8 100644
--- a/constants.properties
+++ b/constants.properties
@@ -29,7 +29,7 @@ snakeYamlVersion=1.19
 caffeineVersion=2.7.0
 metricsVersion=4.1.0
 metricsNewRelicVersion=1.1.1
-djvmVersion=1.0-RC02
+djvmVersion=1.0-RC03
 openSourceBranch=https://github.com/corda/corda/blob/release/os/4.4
 openSourceSamplesBranch=https://github.com/corda/samples/blob/release-V4
 jolokiaAgentVersion=1.6.1
diff --git a/node/src/main/kotlin/net/corda/node/internal/djvm/DeterministicVerifier.kt b/node/src/main/kotlin/net/corda/node/internal/djvm/DeterministicVerifier.kt
index de42d36471..10c0712237 100644
--- a/node/src/main/kotlin/net/corda/node/internal/djvm/DeterministicVerifier.kt
+++ b/node/src/main/kotlin/net/corda/node/internal/djvm/DeterministicVerifier.kt
@@ -19,6 +19,7 @@ import net.corda.djvm.messages.Message
 import net.corda.djvm.rewiring.SandboxClassLoader
 import net.corda.djvm.source.ClassSource
 import net.corda.node.djvm.LtxFactory
+import java.util.function.Function
 
 class DeterministicVerifier(
     ltx: LedgerTransaction,
@@ -27,7 +28,7 @@ class DeterministicVerifier(
 ) : Verifier(ltx, transactionClassLoader) {
 
     override fun verifyContracts() {
-        val result = IsolatedTask(ltx.id.toString(), sandboxConfiguration).run {
+        val result = IsolatedTask(ltx.id.toString(), sandboxConfiguration).run<Any>(Function { classLoader ->
             (classLoader.parent as? SandboxClassLoader)?.apply {
                 /**
                  * We don't need to add either Java APIs or Corda's own classes
@@ -92,7 +93,7 @@ class DeterministicVerifier(
 
             // Now execute the contract verifier task within the sandbox...
             verifier.apply(sandboxTx)
-        }
+        })
 
         with (result.costs) {
             logger.info("Verify {} complete: allocations={}, invocations={}, jumps={}, throws={}",
diff --git a/serialization-djvm/src/test/kotlin/net/corda/serialization/djvm/TestBase.kt b/serialization-djvm/src/test/kotlin/net/corda/serialization/djvm/TestBase.kt
index 9267183820..5f66e1da97 100644
--- a/serialization-djvm/src/test/kotlin/net/corda/serialization/djvm/TestBase.kt
+++ b/serialization-djvm/src/test/kotlin/net/corda/serialization/djvm/TestBase.kt
@@ -102,9 +102,9 @@ abstract class TestBase(type: SandboxType) {
                     it.setMinimumSeverityLevel(minimumSeverityLevel)
                     it.setSandboxOnlyAnnotations(sandboxOnlyAnnotations)
                     it.setVisibleAnnotations(visibleAnnotations)
-                })).use {
-                    action(this)
-                }
+                })).use(Consumer { ctx ->
+                    ctx.action()
+                })
             }
         }.apply {
             uncaughtExceptionHandler = Thread.UncaughtExceptionHandler { _, ex ->