diff --git a/tests/cunit/test_async_perf.c b/tests/cunit/test_async_perf.c
index 75b8f68a659..11e12305512 100644
--- a/tests/cunit/test_async_perf.c
+++ b/tests/cunit/test_async_perf.c
@@ -61,6 +61,9 @@ char dim_name[NDIM4][PIO_MAX_NAME + 1] = {"unlim", "x", "y", "z"};
 
 #define NUM_VAR_SETS 2
 
+/* How long to sleep for "calculation time". */
+#define SLEEP_SECONDS 3
+
 #ifdef USE_MPE
 /* This array holds even numbers for MPE. */
 int test_event[2][TEST_NUM_EVENTS];
@@ -216,6 +219,22 @@ run_darray_async_test(int iosysid, int fmt, int my_rank, int ntasks, int niotask
                 test_stop_mpe_log(TEST_DARRAY_WRITE, msg);
             }
 #endif /* USE_MPE */
+
+            /* Now do some calculations. */
+#ifdef USE_MPE
+            test_start_mpe_log(TEST_CALCULATE);
+#endif /* USE_MPE */
+
+            /* Sleep some seconds away. */
+            sleep(SLEEP_SECONDS);
+
+#ifdef USE_MPE
+            {
+                char msg[MPE_MAX_MSG_LEN + 1];
+                sprintf(msg, "timestep %d", t);
+                test_stop_mpe_log(TEST_CALCULATE, msg);
+            }
+#endif /* USE_MPE */
         }
 
         /* Close the file. */