diff --git a/tests/sys/aio/aio_kqueue_test.c b/tests/sys/aio/aio_kqueue_test.c
--- a/tests/sys/aio/aio_kqueue_test.c
+++ b/tests/sys/aio/aio_kqueue_test.c
@@ -211,8 +211,15 @@
 				printf("PASS: run %d, left %d\n", run,
 				    pending - 1);
 
+			if (j < max_queue_per_proc) {
+				iocb[j] = NULL;
+			} else {
+				printf("FAIL: run %d, result %d; kq_iocb"
+				    " %p not found (should never happen)\n",
+				    run, result, kq_iocb);
+				failed++;
+			}
 			free(kq_iocb);
-			iocb[j] = NULL;
 			pending--;
 			i++;
 		}