diff --git a/src/backend/distributed/commands/table.c b/src/backend/distributed/commands/table.c
index e65f57961ba..665347838ba 100644
--- a/src/backend/distributed/commands/table.c
+++ b/src/backend/distributed/commands/table.c
@@ -3664,6 +3664,17 @@ ErrorIfUnsupportedAlterTableStmt(AlterTableStmt *alterTableStatement)
 				break;
 			}
 
+#if PG_VERSION_NUM >= PG_VERSION_17
+			case AT_SetExpression:
+			{
+				ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								errmsg(
+									"ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION commands "
+									"are currently unsupported.")));
+				break;
+			}
+
+#endif
 #if PG_VERSION_NUM >= PG_VERSION_15
 			case AT_SetAccessMethod:
 #endif
diff --git a/src/test/regress/expected/pg17.out b/src/test/regress/expected/pg17.out
index 23efee4bd6c..0faad6bb12b 100644
--- a/src/test/regress/expected/pg17.out
+++ b/src/test/regress/expected/pg17.out
@@ -1333,6 +1333,47 @@ SELECT b, c FROM forcetest WHERE a = 6;
 
 \pset null ''
 -- End of Testing FORCE_NOT_NULL and FORCE_NULL options
+-- Test for ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION
+-- Step 1: Local table setup (non-distributed)
+CREATE TABLE test_local_table_expr (id int, col int);
+SELECT citus_add_local_table_to_metadata('test_local_table_expr');
+ citus_add_local_table_to_metadata
+---------------------------------------------------------------------
+
+(1 row)
+
+-- Step 2: Attempt to set expression on a Citus local table (should fail)
+ALTER TABLE test_local_table_expr ALTER COLUMN col SET EXPRESSION AS (id * 4);
+ERROR:  ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION commands are currently unsupported.
+-- Step 3: Create and distribute a table
+CREATE TABLE test_distributed_table_expr (id int, col int);
+SELECT create_distributed_table('test_distributed_table_expr', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- Step 4: Attempt to set expression on a distributed table (should fail)
+ALTER TABLE test_distributed_table_expr ALTER COLUMN col SET EXPRESSION AS (id * 4);
+ERROR:  ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION commands are currently unsupported.
+-- Step 5: Create and distribute a partitioned table
+CREATE TABLE test_partitioned_expr (id int, val text) PARTITION BY RANGE (id);
+CREATE TABLE test_partitioned_expr_part1 PARTITION OF test_partitioned_expr
+  FOR VALUES FROM (1) TO (100);
+SELECT create_distributed_table('test_partitioned_expr', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- Step 6: Attempt to set expression on a partitioned, distributed table (should fail)
+ALTER TABLE test_partitioned_expr ALTER COLUMN val SET EXPRESSION AS (id * 4);
+ERROR:  ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION commands are currently unsupported.
+-- Cleanup
+DROP TABLE test_local_table_expr CASCADE;
+DROP TABLE test_distributed_table_expr CASCADE;
+DROP TABLE test_partitioned_expr CASCADE;
+-- End of Test for ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION
 \set VERBOSITY terse
 SET client_min_messages TO WARNING;
 DROP SCHEMA pg17 CASCADE;
diff --git a/src/test/regress/sql/pg17.sql b/src/test/regress/sql/pg17.sql
index ab8528f4b21..1248e760c33 100644
--- a/src/test/regress/sql/pg17.sql
+++ b/src/test/regress/sql/pg17.sql
@@ -711,6 +711,38 @@ SELECT b, c FROM forcetest WHERE a = 6;
 
 -- End of Testing FORCE_NOT_NULL and FORCE_NULL options
 
+-- Test for ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION
+
+-- Step 1: Local table setup (non-distributed)
+CREATE TABLE test_local_table_expr (id int, col int);
+
+SELECT citus_add_local_table_to_metadata('test_local_table_expr');
+
+-- Step 2: Attempt to set expression on a Citus local table (should fail)
+ALTER TABLE test_local_table_expr ALTER COLUMN col SET EXPRESSION AS (id * 4);
+
+-- Step 3: Create and distribute a table
+CREATE TABLE test_distributed_table_expr (id int, col int);
+SELECT create_distributed_table('test_distributed_table_expr', 'id');
+
+-- Step 4: Attempt to set expression on a distributed table (should fail)
+ALTER TABLE test_distributed_table_expr ALTER COLUMN col SET EXPRESSION AS (id * 4);
+
+-- Step 5: Create and distribute a partitioned table
+CREATE TABLE test_partitioned_expr (id int, val text) PARTITION BY RANGE (id);
+CREATE TABLE test_partitioned_expr_part1 PARTITION OF test_partitioned_expr
+  FOR VALUES FROM (1) TO (100);
+SELECT create_distributed_table('test_partitioned_expr', 'id');
+
+-- Step 6: Attempt to set expression on a partitioned, distributed table (should fail)
+ALTER TABLE test_partitioned_expr ALTER COLUMN val SET EXPRESSION AS (id * 4);
+
+-- Cleanup
+DROP TABLE test_local_table_expr CASCADE;
+DROP TABLE test_distributed_table_expr CASCADE;
+DROP TABLE test_partitioned_expr CASCADE;
+-- End of Test for ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION
+
 \set VERBOSITY terse
 SET client_min_messages TO WARNING;
 DROP SCHEMA pg17 CASCADE;