diff --git a/sycl/plugins/level_zero/pi_level_zero.cpp b/sycl/plugins/level_zero/pi_level_zero.cpp
index def60bc219aca..ee96398535c66 100644
--- a/sycl/plugins/level_zero/pi_level_zero.cpp
+++ b/sycl/plugins/level_zero/pi_level_zero.cpp
@@ -6465,15 +6465,15 @@ pi_result piEnqueueEventsWaitWithBarrier(pi_queue Queue,
     }
   }
 
-  // Insert a barrier into each unique command queue using the available
-  // command-lists.
-  std::vector<pi_event> EventWaitVector(CmdLists.size());
-  for (size_t I = 0; I < CmdLists.size(); ++I)
-    if (auto Res = insertBarrierIntoCmdList(CmdLists[I], _pi_ze_event_list_t{},
-                                            EventWaitVector[I], false))
-      return Res;
-
   if (CmdLists.size() > 1) {
+    // Insert a barrier into each unique command queue using the available
+    // command-lists.
+    std::vector<pi_event> EventWaitVector(CmdLists.size());
+    for (size_t I = 0; I < CmdLists.size(); ++I)
+      if (auto Res = insertBarrierIntoCmdList(
+              CmdLists[I], _pi_ze_event_list_t{}, EventWaitVector[I], false))
+        return Res;
+
     // If there were multiple queues we need to create a "convergence" event to
     // be our active barrier. This convergence event is signalled by a barrier
     // on all the events from the barriers we have inserted into each queue.
@@ -6497,10 +6497,13 @@ pi_result piEnqueueEventsWaitWithBarrier(pi_queue Queue,
                                             *Event, IsInternal))
       return Res;
   } else {
-    // If there is only a single queue we have inserted all the barriers we need
-    // and the single result event can be used as our active barrier and used as
-    // the return event.
-    *Event = EventWaitVector[0];
+    PI_ASSERT(CmdLists.size() == 1, PI_ERROR_INVALID_QUEUE);
+    // If there is only a single queue then insert a barrier and the single
+    // result event can be used as our active barrier and used as the return
+    // event. Take into account whether output event is discarded or not.
+    if (auto Res = insertBarrierIntoCmdList(CmdLists[0], _pi_ze_event_list_t{},
+                                            *Event, IsInternal))
+      return Res;
   }
 
   // Execute each command list so the barriers can be encountered.