diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 1f684b81f82..3e2fc8f0b24 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -636,8 +636,6 @@ heap_vacuum_rel(Relation rel, const VacuumParams *params,
 				new_rel_allfrozen;
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
-	PgStat_Counter startreadtime = 0,
-				startwritetime = 0;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	ErrorContextCallback errcallback;
@@ -648,14 +646,7 @@ heap_vacuum_rel(Relation rel, const VacuumParams *params,
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
 							  params->log_vacuum_min_duration >= 0));
 	if (instrument)
-	{
 		pg_rusage_init(&ru0);
-		if (track_io_timing)
-		{
-			startreadtime = pgStatBlockReadTime;
-			startwritetime = pgStatBlockWriteTime;
-		}
-	}
 
 	/* Used for instrumentation and stats report */
 	starttime = GetCurrentTimestamp();
@@ -1176,8 +1167,17 @@ heap_vacuum_rel(Relation rel, const VacuumParams *params,
 			}
 			if (track_io_timing)
 			{
-				double		read_ms = (double) (pgStatBlockReadTime - startreadtime) / 1000;
-				double		write_ms = (double) (pgStatBlockWriteTime - startwritetime) / 1000;
+				/*
+				 * Take the timings from the same buffer usage delta as the
+				 * block counts, so that the parallel workers are included in
+				 * both.
+				 */
+				double		read_ms =
+					INSTR_TIME_GET_MILLISEC(bufferusage.shared_blk_read_time) +
+					INSTR_TIME_GET_MILLISEC(bufferusage.local_blk_read_time);
+				double		write_ms =
+					INSTR_TIME_GET_MILLISEC(bufferusage.shared_blk_write_time) +
+					INSTR_TIME_GET_MILLISEC(bufferusage.local_blk_write_time);
 
 				appendStringInfo(&buf, _("I/O timings: read: %.3f ms, write: %.3f ms\n"),
 								 read_ms, write_ms);