diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 074ddb6b9cd..1c3ad74e7b9 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -14484,6 +14484,9 @@ ATPrepAlterColumnType(List **wqueue,
 		/* Fix collations after all else */
 		assign_expr_collations(pstate, transform);
 
+		/* Expand virtual generated columns in the expr. */
+		transform = expand_generated_columns_in_expr(transform, rel, 1);
+
 		/* Plan the expr now so we can accurately assess the need to rewrite. */
 		transform = (Node *) expression_planner((Expr *) transform);
 
diff --git a/src/test/regress/expected/generated_virtual.out b/src/test/regress/expected/generated_virtual.out
index 47cbd3a82fe..46713f06797 100644
--- a/src/test/regress/expected/generated_virtual.out
+++ b/src/test/regress/expected/generated_virtual.out
@@ -1479,7 +1479,8 @@ create table gtest32 (
   a int primary key,
   b int generated always as (a * 2),
   c int generated always as (10 + 10),
-  d int generated always as (coalesce(a, 100))
+  d int generated always as (coalesce(a, 100)),
+  e int
 );
 insert into gtest32 values (1), (2);
 analyze gtest32;
@@ -1563,41 +1564,44 @@ select t2.* from gtest32 t1 left join gtest32 t2 on false;
                       QUERY PLAN                      
 ------------------------------------------------------
  Nested Loop Left Join
-   Output: a, (a * 2), (20), (COALESCE(a, 100))
+   Output: a, (a * 2), (20), (COALESCE(a, 100)), e
    Join Filter: false
    ->  Seq Scan on generated_virtual_tests.gtest32 t1
-         Output: t1.a, t1.b, t1.c, t1.d
+         Output: t1.a, t1.b, t1.c, t1.d, t1.e
    ->  Result
-         Output: a, 20, COALESCE(a, 100)
+         Output: a, e, 20, COALESCE(a, 100)
          One-Time Filter: false
 (8 rows)
 
 select t2.* from gtest32 t1 left join gtest32 t2 on false;
- a | b | c | d 
----+---+---+---
-   |   |   |  
-   |   |   |  
+ a | b | c | d | e 
+---+---+---+---+---
+   |   |   |   |  
+   |   |   |   |  
 (2 rows)
 
 explain (verbose, costs off)
-select * from gtest32 t group by grouping sets (a, b, c, d) having c = 20;
+select * from gtest32 t group by grouping sets (a, b, c, d, e) having c = 20;
                      QUERY PLAN                      
 -----------------------------------------------------
  HashAggregate
-   Output: a, ((a * 2)), (20), (COALESCE(a, 100))
+   Output: a, ((a * 2)), (20), (COALESCE(a, 100)), e
    Hash Key: t.a
    Hash Key: (t.a * 2)
    Hash Key: 20
    Hash Key: COALESCE(t.a, 100)
+   Hash Key: t.e
    Filter: ((20) = 20)
    ->  Seq Scan on generated_virtual_tests.gtest32 t
-         Output: a, (a * 2), 20, COALESCE(a, 100)
-(9 rows)
+         Output: a, (a * 2), 20, COALESCE(a, 100), e
+(10 rows)
 
-select * from gtest32 t group by grouping sets (a, b, c, d) having c = 20;
- a | b | c  | d 
----+---+----+---
-   |   | 20 |  
+select * from gtest32 t group by grouping sets (a, b, c, d, e) having c = 20;
+ a | b | c  | d | e 
+---+---+----+---+---
+   |   | 20 |   |  
 (1 row)
 
+-- Ensure that the virtual generated columns in ALTER COLUMN TYPE USING expression are expanded
+alter table gtest32 alter column e type bigint using b;
 drop table gtest32;
diff --git a/src/test/regress/sql/generated_virtual.sql b/src/test/regress/sql/generated_virtual.sql
index c731d123763..6fa986515b9 100644
--- a/src/test/regress/sql/generated_virtual.sql
+++ b/src/test/regress/sql/generated_virtual.sql
@@ -797,7 +797,8 @@ create table gtest32 (
   a int primary key,
   b int generated always as (a * 2),
   c int generated always as (10 + 10),
-  d int generated always as (coalesce(a, 100))
+  d int generated always as (coalesce(a, 100)),
+  e int
 );
 
 insert into gtest32 values (1), (2);
@@ -838,7 +839,10 @@ select t2.* from gtest32 t1 left join gtest32 t2 on false;
 select t2.* from gtest32 t1 left join gtest32 t2 on false;
 
 explain (verbose, costs off)
-select * from gtest32 t group by grouping sets (a, b, c, d) having c = 20;
-select * from gtest32 t group by grouping sets (a, b, c, d) having c = 20;
+select * from gtest32 t group by grouping sets (a, b, c, d, e) having c = 20;
+select * from gtest32 t group by grouping sets (a, b, c, d, e) having c = 20;
+
+-- Ensure that the virtual generated columns in ALTER COLUMN TYPE USING expression are expanded
+alter table gtest32 alter column e type bigint using b;
 
 drop table gtest32;