diff --git a/providers/null/src/main/java/org/onosproject/provider/nil/NullPacketProvider.java b/providers/null/src/main/java/org/onosproject/provider/nil/NullPacketProvider.java
index a1baec9..674b33f 100644
--- a/providers/null/src/main/java/org/onosproject/provider/nil/NullPacketProvider.java
+++ b/providers/null/src/main/java/org/onosproject/provider/nil/NullPacketProvider.java
@@ -136,8 +136,8 @@
 
         @Override
         public void run(Timeout to) {
-            if (!devices.isEmpty()) {
-                sendEvent(devices.get(currentDevice));
+            if (!devices.isEmpty() && !to.isCancelled()) {
+                sendEvent(devices.get(Math.max(currentDevice, devices.size())));
                 currentDevice = (currentDevice + 1) % devices.size();
                 timeout = timer.newTimeout(to.getTask(), delay, TimeUnit.MILLISECONDS);
             }