diff --git a/samples/irs-demo/src/main/kotlin/net/corda/irs/flows/FixingFlow.kt b/samples/irs-demo/src/main/kotlin/net/corda/irs/flows/FixingFlow.kt
index 67245913af..041535441a 100644
--- a/samples/irs-demo/src/main/kotlin/net/corda/irs/flows/FixingFlow.kt
+++ b/samples/irs-demo/src/main/kotlin/net/corda/irs/flows/FixingFlow.kt
@@ -132,8 +132,9 @@ object FixingFlow {
      *
      * TODO: Replace [FixingSession] and [FixingSessionInitiationHandler] with generic session initiation logic once it exists.
      */
-    class FixingRoleDecider(val ref: StateRef,
-                            override val progressTracker: ProgressTracker = tracker()) : FlowLogic<Unit>() {
+    class FixingRoleDecider(val ref: StateRef, override val progressTracker: ProgressTracker) : FlowLogic<Unit>() {
+        @Suppress("unused")  // Used via reflection.
+        constructor(ref: StateRef) : this(ref, tracker())
 
         companion object {
             class LOADING() : ProgressTracker.Step("Loading state to decide fixing role")