diff --git a/src/H5ESint.c b/src/H5ESint.c
index 5f2ad7cdc2..6ce09d5e12 100644
--- a/src/H5ESint.c
+++ b/src/H5ESint.c
@@ -587,14 +587,27 @@ H5ES__op_complete(H5ES_t *es, H5ES_event_t *ev, H5VL_request_status_t ev_status)
 
             /* Set appropriate info for callback */
             if (H5VL_REQUEST_STATUS_SUCCEED == ev_status) {
+                uint64_t supported;     /* Whether 'execution time' operation is supported by VOL connector */
+
                 /* Translate status */
                 op_status = H5ES_STATUS_SUCCEED;
 
-                /* Retrieve the execution time info */
-                if (H5VL_request_specific(ev->request, H5VL_REQUEST_GET_EXEC_TIME, &ev->op_info.op_exec_ts,
-                                          &ev->op_info.op_exec_time) < 0)
-                    HGOTO_ERROR(H5E_EVENTSET, H5E_CANTGET, FAIL,
-                                "unable to retrieve execution time info for operation")
+                /* Check for 'execution time' callback */
+                supported = 0;
+                if (H5VL_introspect_opt_query(ev->request, H5VL_SUBCLS_REQUEST, H5VL_REQUEST_GET_EXEC_TIME, &supported) < 0)
+                    HGOTO_ERROR(H5E_EVENTSET, H5E_CANTGET, FAIL, "can't check for 'get execution time' operation")
+                if (supported & H5VL_OPT_QUERY_SUPPORTED) {
+                    /* Retrieve the execution time info */
+                    if (H5VL_request_optional(ev->request, H5VL_REQUEST_GET_EXEC_TIME, &ev->op_info.op_exec_ts,
+                                              &ev->op_info.op_exec_time) < 0)
+                        HGOTO_ERROR(H5E_EVENTSET, H5E_CANTGET, FAIL,
+                                    "unable to retrieve execution time info for operation")
+                } /* end if */
+                else {
+                    /* Set invalid values for execution timestamp and duration */
+                    ev->op_info.op_exec_ts = UINT64_MAX;
+                    ev->op_info.op_exec_time = UINT64_MAX;
+                } /* end else */
             }
             else
                 /* Translate status */
diff --git a/src/H5VLconnector.h b/src/H5VLconnector.h
index 25527dee80..49edea5505 100644
--- a/src/H5VLconnector.h
+++ b/src/H5VLconnector.h
@@ -202,13 +202,15 @@ typedef enum H5VL_request_status_t {
 /* types for async request SPECIFIC callback */
 typedef enum H5VL_request_specific_t {
     H5VL_REQUEST_GET_ERR_STACK,     /* Retrieve error stack for failed operation */
-    H5VL_REQUEST_GET_TIME_ESTIMATE, /* Retrieve time estimate for completing operation */
-    H5VL_REQUEST_GET_EXEC_TIME      /* Retrieve execution time for operation */
+    H5VL_REQUEST_GET_TIME_ESTIMATE  /* Retrieve time estimate for completing operation */
 } H5VL_request_specific_t;
 
-/* Typedef and values for native VOL connector request optional VOL operations */
+/* Typedef and values for VOL connector request optional VOL operations */
+/* (This is an unusual case - we'd like to pre-define these operations, even
+ *      though the native VOL connector doesn't implement them. QAK - 2021/04/10)
+ */
 typedef int H5VL_request_optional_t;
-/* (No optional request VOL operations currently) */
+#define H5VL_REQUEST_GET_EXEC_TIME 0      /* Retrieve execution time for operation */
 
 /* types for 'blob' SPECIFIC callback */
 typedef enum H5VL_blob_specific_t {
diff --git a/src/H5trace.c b/src/H5trace.c
index ef945c36a9..64758c188a 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -3364,10 +3364,6 @@ H5_trace_args(H5RS_str_t *rs, const char *type, va_list ap)
                                     H5RS_acat(rs, "H5VL_REQUEST_GET_TIME_ESTIMATE");
                                     break;
 
-                                case H5VL_REQUEST_GET_EXEC_TIME:
-                                    H5RS_acat(rs, "H5VL_REQUEST_GET_EXEC_TIME");
-                                    break;
-
                                 default:
                                     H5RS_asprintf_cat(rs, "%ld", (long)specific);
                                     break;
@@ -3715,7 +3711,15 @@ H5_trace_args(H5RS_str_t *rs, const char *type, va_list ap)
                         {
                             H5VL_request_optional_t optional = (H5VL_request_optional_t)HDva_arg(ap, int);
 
-                            H5RS_asprintf_cat(rs, "%ld", (long)optional);
+                            switch (optional) {
+                                case H5VL_REQUEST_GET_EXEC_TIME:
+                                    H5RS_acat(rs, "H5VL_REQUEST_GET_EXEC_TIME");
+                                    break;
+
+                                default:
+                                    H5RS_asprintf_cat(rs, "%ld", (long)optional);
+                                    break;
+                            } /* end switch */
                         } /* end block */
                         break;