diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 98eb40cc47e..d3ff5aed629 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -89,9 +89,10 @@ create_upper_paths_hook_type create_upper_paths_hook = NULL;
 #define EXPRKIND_APPINFO			7
 #define EXPRKIND_PHV				8
 #define EXPRKIND_TABLESAMPLE		9
-#define EXPRKIND_ARBITER_ELEM		10
-#define EXPRKIND_TABLEFUNC			11
-#define EXPRKIND_TABLEFUNC_LATERAL	12
+#define EXPRKIND_TABLESAMPLE_LATERAL	10
+#define EXPRKIND_ARBITER_ELEM		11
+#define EXPRKIND_TABLEFUNC			12
+#define EXPRKIND_TABLEFUNC_LATERAL	13
 
 /* Passthrough data for standard_qp_callback */
 typedef struct
@@ -915,10 +916,15 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
 		if (rte->rtekind == RTE_RELATION)
 		{
 			if (rte->tablesample)
+			{
+				/* Preprocess the tablesample expression(s) fully */
+				kind = rte->lateral ? EXPRKIND_TABLESAMPLE_LATERAL :
+					EXPRKIND_TABLESAMPLE;
 				rte->tablesample = (TableSampleClause *)
 					preprocess_expression(root,
 										  (Node *) rte->tablesample,
-										  EXPRKIND_TABLESAMPLE);
+										  kind);
+			}
 		}
 		else if (rte->rtekind == RTE_SUBQUERY)
 		{
diff --git a/src/test/regress/expected/tablesample.out b/src/test/regress/expected/tablesample.out
index 60bb4e8e3e6..0534b530793 100644
--- a/src/test/regress/expected/tablesample.out
+++ b/src/test/regress/expected/tablesample.out
@@ -279,6 +279,38 @@ select pct, count(unique1) from
  100 | 10000
 (1 row)
 
+-- check that a join alias Var in a pulled-up LATERAL subquery's TABLESAMPLE
+-- clause gets flattened
+explain (costs off)
+select pct, count(unique1) from
+  ((values (0)) v(pct) full join (values (100)) w(pct) using (pct)),
+  lateral (select * from tenk1 tablesample bernoulli (pct)) ss
+  group by pct order by pct;
+                           QUERY PLAN                           
+----------------------------------------------------------------
+ GroupAggregate
+   Group Key: (COALESCE((0), (100)))
+   ->  Sort
+         Sort Key: (COALESCE((0), (100)))
+         ->  Nested Loop
+               ->  Hash Full Join
+                     Hash Cond: ((0) = (100))
+                     ->  Result
+                     ->  Hash
+                           ->  Result
+               ->  Sample Scan on tenk1
+                     Sampling: bernoulli (COALESCE((0), (100)))
+(12 rows)
+
+select pct, count(unique1) from
+  ((values (0)) v(pct) full join (values (100)) w(pct) using (pct)),
+  lateral (select * from tenk1 tablesample bernoulli (pct)) ss
+  group by pct order by pct;
+ pct | count 
+-----+-------
+ 100 | 10000
+(1 row)
+
 -- errors
 SELECT id FROM test_tablesample TABLESAMPLE FOOBAR (1);
 ERROR:  tablesample method foobar does not exist
diff --git a/src/test/regress/sql/tablesample.sql b/src/test/regress/sql/tablesample.sql
index aa17994277c..7dd7738e530 100644
--- a/src/test/regress/sql/tablesample.sql
+++ b/src/test/regress/sql/tablesample.sql
@@ -82,6 +82,18 @@ select pct, count(unique1) from
   lateral (select * from tenk1 tablesample system (pct)) ss
   group by pct;
 
+-- check that a join alias Var in a pulled-up LATERAL subquery's TABLESAMPLE
+-- clause gets flattened
+explain (costs off)
+select pct, count(unique1) from
+  ((values (0)) v(pct) full join (values (100)) w(pct) using (pct)),
+  lateral (select * from tenk1 tablesample bernoulli (pct)) ss
+  group by pct order by pct;
+select pct, count(unique1) from
+  ((values (0)) v(pct) full join (values (100)) w(pct) using (pct)),
+  lateral (select * from tenk1 tablesample bernoulli (pct)) ss
+  group by pct order by pct;
+
 -- errors
 SELECT id FROM test_tablesample TABLESAMPLE FOOBAR (1);