diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 8c58808686..73677be59e 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -2506,8 +2506,7 @@ CopyFrom(CopyState cstate)
 
 	for (;;)
 	{
-		TupleTableSlot *slot,
-				   *oldslot;
+		TupleTableSlot *slot;
 		bool		skip_tuple;
 		Oid			loaded_oid = InvalidOid;
 
@@ -2549,7 +2548,6 @@ CopyFrom(CopyState cstate)
 		ExecStoreTuple(tuple, slot, InvalidBuffer, false);
 
 		/* Determine the partition to heap_insert the tuple into */
-		oldslot = slot;
 		if (cstate->partition_dispatch_info)
 		{
 			int			leaf_part_index;
@@ -2651,7 +2649,7 @@ CopyFrom(CopyState cstate)
 				/* Check the constraints of the tuple */
 				if (cstate->rel->rd_att->constr ||
 					resultRelInfo->ri_PartitionCheck)
-					ExecConstraints(resultRelInfo, slot, oldslot, estate);
+					ExecConstraints(resultRelInfo, slot, estate);
 
 				if (useHeapMultiInsert)
 				{
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 920b12072f..5c12fb457d 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1824,14 +1824,12 @@ ExecPartitionCheck(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
  * the partition constraint, if any.
  *
  * Note: 'slot' contains the tuple to check the constraints of, which may
- * have been converted from the original input tuple after tuple routing,
- * while 'orig_slot' contains the original tuple to be shown in the message,
- * if an error occurs.
+ * have been converted from the original input tuple after tuple routing.
+ * 'resultRelInfo' is the original result relation, before tuple routing.
  */
 void
 ExecConstraints(ResultRelInfo *resultRelInfo,
-				TupleTableSlot *slot, TupleTableSlot *orig_slot,
-				EState *estate)
+				TupleTableSlot *slot, EState *estate)
 {
 	Relation	rel = resultRelInfo->ri_RelationDesc;
 	TupleDesc	tupdesc = RelationGetDescr(rel);
@@ -1854,23 +1852,37 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 			{
 				char	   *val_desc;
 				Relation	orig_rel = rel;
-				TupleDesc	orig_tupdesc = tupdesc;
+				TupleDesc	orig_tupdesc = RelationGetDescr(rel);
 
 				/*
-				 * choose the correct relation to build val_desc from the
-				 * tuple contained in orig_slot
+				 * If the tuple has been routed, it's been converted to the
+				 * partition's rowtype, which might differ from the root
+				 * table's.  We must convert it back to the root table's
+				 * rowtype so that val_desc shown error message matches the
+				 * input tuple.
 				 */
 				if (resultRelInfo->ri_PartitionRoot)
 				{
+					HeapTuple	tuple = ExecFetchSlotTuple(slot);
+					TupleConversionMap	*map;
+
 					rel = resultRelInfo->ri_PartitionRoot;
 					tupdesc = RelationGetDescr(rel);
+					/* a reverse map */
+					map = convert_tuples_by_name(orig_tupdesc, tupdesc,
+								gettext_noop("could not convert row type"));
+					if (map != NULL)
+					{
+						tuple = do_convert_tuple(tuple, map);
+						ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+					}
 				}
 
 				insertedCols = GetInsertedColumns(resultRelInfo, estate);
 				updatedCols = GetUpdatedColumns(resultRelInfo, estate);
 				modifiedCols = bms_union(insertedCols, updatedCols);
 				val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
-														 orig_slot,
+														 slot,
 														 tupdesc,
 														 modifiedCols,
 														 64);
@@ -1897,15 +1909,27 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 			/* See the comment above. */
 			if (resultRelInfo->ri_PartitionRoot)
 			{
+				HeapTuple	tuple = ExecFetchSlotTuple(slot);
+				TupleDesc	old_tupdesc = RelationGetDescr(rel);
+				TupleConversionMap	*map;
+
 				rel = resultRelInfo->ri_PartitionRoot;
 				tupdesc = RelationGetDescr(rel);
+				/* a reverse map */
+				map = convert_tuples_by_name(old_tupdesc, tupdesc,
+							gettext_noop("could not convert row type"));
+				if (map != NULL)
+				{
+					tuple = do_convert_tuple(tuple, map);
+					ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+				}
 			}
 
 			insertedCols = GetInsertedColumns(resultRelInfo, estate);
 			updatedCols = GetUpdatedColumns(resultRelInfo, estate);
 			modifiedCols = bms_union(insertedCols, updatedCols);
 			val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
-													 orig_slot,
+													 slot,
 													 tupdesc,
 													 modifiedCols,
 													 64);
@@ -1927,15 +1951,27 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 		/* See the comment above. */
 		if (resultRelInfo->ri_PartitionRoot)
 		{
+			HeapTuple	tuple = ExecFetchSlotTuple(slot);
+			TupleDesc	old_tupdesc = RelationGetDescr(rel);
+			TupleConversionMap	*map;
+
 			rel = resultRelInfo->ri_PartitionRoot;
 			tupdesc = RelationGetDescr(rel);
+			/* a reverse map */
+			map = convert_tuples_by_name(old_tupdesc, tupdesc,
+						gettext_noop("could not convert row type"));
+			if (map != NULL)
+			{
+				tuple = do_convert_tuple(tuple, map);
+				ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+			}
 		}
 
 		insertedCols = GetInsertedColumns(resultRelInfo, estate);
 		updatedCols = GetUpdatedColumns(resultRelInfo, estate);
 		modifiedCols = bms_union(insertedCols, updatedCols);
 		val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
-												 orig_slot,
+												 slot,
 												 tupdesc,
 												 modifiedCols,
 												 64);
diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c
index f20d728ad5..327a0bad38 100644
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -389,7 +389,7 @@ ExecSimpleRelationInsert(EState *estate, TupleTableSlot *slot)
 
 		/* Check the constraints of the tuple */
 		if (rel->rd_att->constr)
-			ExecConstraints(resultRelInfo, slot, slot, estate);
+			ExecConstraints(resultRelInfo, slot, estate);
 
 		/* Store the slot into tuple that we can inspect. */
 		tuple = ExecMaterializeSlot(slot);
@@ -448,7 +448,7 @@ ExecSimpleRelationUpdate(EState *estate, EPQState *epqstate,
 
 		/* Check the constraints of the tuple */
 		if (rel->rd_att->constr)
-			ExecConstraints(resultRelInfo, slot, slot, estate);
+			ExecConstraints(resultRelInfo, slot, estate);
 
 		/* Store the slot into tuple that we can write. */
 		tuple = ExecMaterializeSlot(slot);
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 0b524e0b7c..00b736c22c 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -263,8 +263,7 @@ ExecInsert(ModifyTableState *mtstate,
 	Relation	resultRelationDesc;
 	Oid			newId;
 	List	   *recheckIndexes = NIL;
-	TupleTableSlot *oldslot = slot,
-			   *result = NULL;
+	TupleTableSlot *result = NULL;
 
 	/*
 	 * get the heap tuple out of the tuple table slot, making sure we have a
@@ -435,7 +434,7 @@ ExecInsert(ModifyTableState *mtstate,
 		 * Check the constraints of the tuple
 		 */
 		if (resultRelationDesc->rd_att->constr || resultRelInfo->ri_PartitionCheck)
-			ExecConstraints(resultRelInfo, slot, oldslot, estate);
+			ExecConstraints(resultRelInfo, slot, estate);
 
 		if (onconflict != ONCONFLICT_NONE && resultRelInfo->ri_NumIndices > 0)
 		{
@@ -993,7 +992,7 @@ lreplace:;
 		 * tuple-routing is performed here, hence the slot remains unchanged.
 		 */
 		if (resultRelationDesc->rd_att->constr || resultRelInfo->ri_PartitionCheck)
-			ExecConstraints(resultRelInfo, slot, slot, estate);
+			ExecConstraints(resultRelInfo, slot, estate);
 
 		/*
 		 * replace the heap tuple
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index d3849b93eb..f7f3189a1a 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -186,8 +186,7 @@ extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
-				TupleTableSlot *slot, TupleTableSlot *orig_slot,
-				EState *estate);
+				TupleTableSlot *slot, EState *estate);
 extern void ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
 					 TupleTableSlot *slot, EState *estate);
 extern LockTupleMode ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo);
diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out
index 7fafa98212..6f34b1c640 100644
--- a/src/test/regress/expected/insert.out
+++ b/src/test/regress/expected/insert.out
@@ -354,11 +354,26 @@ ERROR:  no partition of relation "mlparted1" found for row
 DETAIL:  Partition key of the failing row contains ((b + 0)) = (5).
 truncate mlparted;
 alter table mlparted add constraint check_b check (b = 3);
--- check that correct input row is shown when constraint check_b fails on mlparted11
--- after "(1, 2)" is routed to it
+-- have a BR trigger modify the row such that the check_b is violated
+create function mlparted11_trig_fn()
+returns trigger AS
+$$
+begin
+  NEW.b := 4;
+  return NEW;
+end;
+$$
+language plpgsql;
+create trigger mlparted11_trig before insert ON mlparted11
+  for each row execute procedure mlparted11_trig_fn();
+-- check that the correct row is shown when constraint check_b fails after
+-- "(1, 2)" is routed to mlparted11 (actually "(1, 4)" would be shown due
+-- to the BR trigger mlparted11_trig_fn)
 insert into mlparted values (1, 2);
 ERROR:  new row for relation "mlparted11" violates check constraint "check_b"
-DETAIL:  Failing row contains (1, 2).
+DETAIL:  Failing row contains (1, 4).
+drop trigger mlparted11_trig on mlparted11;
+drop function mlparted11_trig_fn();
 -- check that inserting into an internal partition successfully results in
 -- checking its partition constraint before inserting into the leaf partition
 -- selected by tuple-routing
diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql
index f9c00705a2..020854c960 100644
--- a/src/test/regress/sql/insert.sql
+++ b/src/test/regress/sql/insert.sql
@@ -217,9 +217,26 @@ insert into mlparted (a, b) values (1, 5);
 
 truncate mlparted;
 alter table mlparted add constraint check_b check (b = 3);
--- check that correct input row is shown when constraint check_b fails on mlparted11
--- after "(1, 2)" is routed to it
+
+-- have a BR trigger modify the row such that the check_b is violated
+create function mlparted11_trig_fn()
+returns trigger AS
+$$
+begin
+  NEW.b := 4;
+  return NEW;
+end;
+$$
+language plpgsql;
+create trigger mlparted11_trig before insert ON mlparted11
+  for each row execute procedure mlparted11_trig_fn();
+
+-- check that the correct row is shown when constraint check_b fails after
+-- "(1, 2)" is routed to mlparted11 (actually "(1, 4)" would be shown due
+-- to the BR trigger mlparted11_trig_fn)
 insert into mlparted values (1, 2);
+drop trigger mlparted11_trig on mlparted11;
+drop function mlparted11_trig_fn();
 
 -- check that inserting into an internal partition successfully results in
 -- checking its partition constraint before inserting into the leaf partition