diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index 53c5254..6a6bf20 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -919,14 +919,25 @@ ExecParallelRetrieveInstrumentation(PlanState *planstate,
 	 * regular instrumentation information, which is the per-query context.
 	 * Switch into per-query memory context.
 	 */
-	oldcontext = MemoryContextSwitchTo(planstate->state->es_query_cxt);
-	ibytes = mul_size(instrumentation->num_workers, sizeof(Instrumentation));
-	planstate->worker_instrument =
-		palloc(ibytes + offsetof(WorkerInstrumentation, instrument));
-	MemoryContextSwitchTo(oldcontext);
+	if (!planstate->worker_instrument)
+	{
+		oldcontext = MemoryContextSwitchTo(planstate->state->es_query_cxt);
+		ibytes = mul_size(instrumentation->num_workers, sizeof(Instrumentation));
+		planstate->worker_instrument =
+			palloc(ibytes + offsetof(WorkerInstrumentation, instrument));
+		MemoryContextSwitchTo(oldcontext);
+
+		for (n = 0; n < instrumentation->num_workers; ++n)
+			InstrInit(&planstate->worker_instrument->instrument[n],
+					  planstate->state->es_instrument);
+	}
 
 	planstate->worker_instrument->num_workers = instrumentation->num_workers;
-	memcpy(&planstate->worker_instrument->instrument, instrument, ibytes);
+
+	/* Accumulate the per-worker detail. */
+	for (n = 0; n < instrumentation->num_workers; ++n)
+		InstrAggNode(&planstate->worker_instrument->instrument[n],
+					 &instrument[n]);
 
 	/*
 	 * Perform any node-type-specific work that needs to be done.  Currently,
@@ -989,8 +1000,20 @@ ExecParallelFinish(ParallelExecutorInfo *pei)
 
 	/* Finally, accumulate instrumentation, if any. */
 	if (pei->instrumentation)
+	{
+		Instrumentation *instrument;
+		SharedExecutorInstrumentation *sh_instr;
+
+		sh_instr = pei->instrumentation;
+
 		ExecParallelRetrieveInstrumentation(pei->planstate,
-											pei->instrumentation);
+											sh_instr);
+
+		/* Clear the instrumentation space for next time. */
+		instrument = GetInstrumentationArray(sh_instr);
+		for (i = 0; i < sh_instr->num_workers * sh_instr->num_plan_nodes; ++i)
+			InstrInit(&instrument[i], pei->planstate->state->es_instrument);
+	}
 
 	pei->finished = true;
 }
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index d1d5b22..681f84a 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -378,7 +378,27 @@ select count(*) from bmscantest where a>1;
  99999
 (1 row)
 
+-- test accumulation of stats for parallel node
 reset enable_seqscan;
+alter table tenk2 set (parallel_workers = 0);
+explain (analyze, timing off, summary off, costs off)
+	select count(*) from tenk1, tenk2 where tenk1.hundred > 1 and tenk2.thousand=0; 
+                                QUERY PLAN                                
+--------------------------------------------------------------------------
+ Aggregate (actual rows=1 loops=1)
+   ->  Nested Loop (actual rows=98000 loops=1)
+         ->  Seq Scan on tenk2 (actual rows=10 loops=1)
+               Filter: (thousand = 0)
+               Rows Removed by Filter: 9990
+         ->  Gather (actual rows=9800 loops=10)
+               Workers Planned: 4
+               Workers Launched: 4
+               ->  Parallel Seq Scan on tenk1 (actual rows=1960 loops=50)
+                     Filter: (hundred > 1)
+                     Rows Removed by Filter: 40
+(11 rows)
+
+alter table tenk2 reset (parallel_workers);
 reset enable_indexscan;
 reset enable_hashjoin;
 reset enable_mergejoin;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index bb4e34a..0c7353f 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -149,7 +149,13 @@ insert into bmscantest select r, 'fooooooooooooooooooooooooooooooooooooooooooooo
 create index i_bmtest ON bmscantest(a);
 select count(*) from bmscantest where a>1;
 
+-- test accumulation of stats for parallel node
 reset enable_seqscan;
+alter table tenk2 set (parallel_workers = 0);
+explain (analyze, timing off, summary off, costs off)
+	select count(*) from tenk1, tenk2 where tenk1.hundred > 1 and tenk2.thousand=0; 
+alter table tenk2 reset (parallel_workers);
+
 reset enable_indexscan;
 reset enable_hashjoin;
 reset enable_mergejoin;