diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index d4eaf30815b..1ef8b355116 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8752,17 +8752,12 @@ static void
 ATPrepDropExpression(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode)
 {
 	/*
-	 * Reject ONLY if there are child tables.  We could implement this, but it
-	 * is a bit complicated.  GENERATED clauses must be attached to the column
-	 * definition and cannot be added later like DEFAULT, so if a child table
-	 * has a generation expression that the parent does not have, the child
-	 * column will necessarily be an attislocal column.  So to implement ONLY
-	 * here, we'd need extra code to update attislocal of the direct child
-	 * tables, somewhat similar to how DROP COLUMN does it, so that the
-	 * resulting state can be properly dumped and restored.
+	 * Reject ONLY if there are child tables -- but only, of course, at the
+	 * top of the tree, otherwise it'd be impossible to run this command with
+	 * trees deeper than two levels.  Caller already got lock.
 	 */
-	if (!recurse &&
-		find_inheritance_children(RelationGetRelid(rel), lockmode))
+	if (!recurse && !recursing &&
+		find_inheritance_children(RelationGetRelid(rel), NoLock))
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("ALTER TABLE / DROP EXPRESSION must be applied to child tables too")));
diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_stored.out
index 86a04548a02..77fcd9002c6 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_stored.out
@@ -1329,6 +1329,56 @@ Inherits: gtest30
 
 ALTER TABLE gtest30_1 ALTER COLUMN b DROP EXPRESSION;  -- error
 ERROR:  cannot drop generation expression from inherited column
+BEGIN;
+CREATE TABLE gtest30_1_1 () INHERITS (gtest30_1);
+ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
+\d gtest30_1_1
+    Table "generated_stored_tests.gtest30_1_1"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+Inherits: gtest30_1
+
+ROLLBACK;
+-- test drop expression with subpartitions
+CREATE TABLE gtest_root (a int, b int, c int GENERATED ALWAYS AS (a + b) STORED) PARTITION BY LIST (a);
+CREATE TABLE gtest_node PARTITION OF gtest_root FOR VALUES IN (1) PARTITION BY LIST (b);
+CREATE TABLE gtest_leaf PARTITION OF gtest_node FOR VALUES IN (1);
+ALTER TABLE gtest_node ALTER COLUMN c DROP EXPRESSION;  -- fails
+ERROR:  cannot drop generation expression from inherited column
+ALTER TABLE ONLY gtest_root ALTER COLUMN c DROP EXPRESSION;  -- fails
+ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
+ALTER TABLE gtest_root ALTER COLUMN c DROP EXPRESSION;
+\d gtest_(root|node|leaf)
+     Table "generated_stored_tests.gtest_leaf"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+ c      | integer |           |          | 
+Partition of: gtest_node FOR VALUES IN (1)
+
+Partitioned table "generated_stored_tests.gtest_node"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+ c      | integer |           |          | 
+Partition of: gtest_root FOR VALUES IN (1)
+Partition key: LIST (b)
+Number of partitions: 1 (Use \d+ to list them.)
+
+Partitioned table "generated_stored_tests.gtest_root"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+ c      | integer |           |          | 
+Partition key: LIST (a)
+Number of partitions: 1 (Use \d+ to list them.)
+
+DROP TABLE gtest_root;
 -- composite type dependencies
 CREATE TABLE gtest31_1 (a int, b text GENERATED ALWAYS AS ('hello') STORED, c text);
 CREATE TABLE gtest31_2 (x int, y gtest31_1);
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_stored.sql
index 6abae289ffe..9ba83c6f5ab 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_stored.sql
@@ -597,6 +597,21 @@ ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
 \d gtest30
 \d gtest30_1
 ALTER TABLE gtest30_1 ALTER COLUMN b DROP EXPRESSION;  -- error
+BEGIN;
+CREATE TABLE gtest30_1_1 () INHERITS (gtest30_1);
+ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
+\d gtest30_1_1
+ROLLBACK;
+
+-- test drop expression with subpartitions
+CREATE TABLE gtest_root (a int, b int, c int GENERATED ALWAYS AS (a + b) STORED) PARTITION BY LIST (a);
+CREATE TABLE gtest_node PARTITION OF gtest_root FOR VALUES IN (1) PARTITION BY LIST (b);
+CREATE TABLE gtest_leaf PARTITION OF gtest_node FOR VALUES IN (1);
+ALTER TABLE gtest_node ALTER COLUMN c DROP EXPRESSION;  -- fails
+ALTER TABLE ONLY gtest_root ALTER COLUMN c DROP EXPRESSION;  -- fails
+ALTER TABLE gtest_root ALTER COLUMN c DROP EXPRESSION;
+\d gtest_(root|node|leaf)
+DROP TABLE gtest_root;
 
 -- composite type dependencies
 CREATE TABLE gtest31_1 (a int, b text GENERATED ALWAYS AS ('hello') STORED, c text);