diff --git a/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/InternalMockNetwork.kt b/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/InternalMockNetwork.kt
index 5cac265b8b..aea0e9d5d0 100644
--- a/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/InternalMockNetwork.kt
+++ b/testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/InternalMockNetwork.kt
@@ -550,7 +550,11 @@ open class InternalMockNetwork(cordappPackages: List<String> = emptyList(),
 
         return allActiveFlows.any {
             val flowState = it.snapshot().checkpoint.flowState
-            flowState is FlowState.Started && flowState.flowIORequest is FlowIORequest.ExecuteAsyncOperation
+            flowState is FlowState.Started && when (flowState.flowIORequest) {
+                is FlowIORequest.ExecuteAsyncOperation -> true
+                is FlowIORequest.Sleep -> true
+                else -> false
+            }
         }
     }