diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 431e62e389..53ff26774a 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -3020,15 +3020,29 @@ check_nested_generated_walker(Node *node, void *context)
 		AttrNumber	attnum;
 
 		relid = rt_fetch(var->varno, pstate->p_rtable)->relid;
+		if (!OidIsValid(relid))
+			return false;		/* XXX shouldn't we raise an error? */
+
 		attnum = var->varattno;
 
-		if (OidIsValid(relid) && AttributeNumberIsValid(attnum) && get_attgenerated(relid, attnum))
+		if (attnum > 0 && get_attgenerated(relid, attnum))
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 					 errmsg("cannot use generated column \"%s\" in column generation expression",
 							get_attname(relid, attnum, false)),
 					 errdetail("A generated column cannot reference another generated column."),
 					 parser_errposition(pstate, var->location)));
+		if (attnum == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("cannot use whole-row variable in column generation expression"),
+					 parser_errposition(pstate, var->location)));
+		if (attnum < 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("cannot use system column \"%s\" in column generation expression",
+							get_attname(relid, attnum, false)),
+					 parser_errposition(pstate, var->location)));
 
 		return false;
 	}
diff --git a/src/test/regress/expected/generated.out b/src/test/regress/expected/generated.out
index 675773f0c1..896b568165 100644
--- a/src/test/regress/expected/generated.out
+++ b/src/test/regress/expected/generated.out
@@ -46,6 +46,16 @@ ERROR:  cannot use generated column "b" in column generation expression
 LINE 1: ...AYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STO...
                                                              ^
 DETAIL:  A generated column cannot reference another generated column.
+-- a whole-row var is a self-reference on steroids
+CREATE TABLE gtest_err_2c (a int PRIMARY KEY, b int GENERATED ALWAYS AS (length(gtest_err_2c::text)) STORED);
+ERROR:  cannot use whole-row variable in column generation expression
+LINE 1: ...nt PRIMARY KEY, b int GENERATED ALWAYS AS (length(gtest_err_...
+                                                             ^
+-- no system columns, either, as those aren't known when generation occurs
+CREATE TABLE gtest_err_2d (a int PRIMARY KEY, b oid GENERATED ALWAYS AS (tableoid) STORED);
+ERROR:  cannot use system column "tableoid" in column generation expression
+LINE 1: ...2d (a int PRIMARY KEY, b oid GENERATED ALWAYS AS (tableoid) ...
+                                                             ^
 -- invalid reference
 CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
 ERROR:  column "c" does not exist
@@ -452,19 +462,6 @@ SELECT * FROM gtest4;
 
 DROP TABLE gtest4;
 DROP TYPE double_int;
--- using tableoid is allowed
-CREATE TABLE gtest_tableoid (
-  a int PRIMARY KEY,
-  b bool GENERATED ALWAYS AS (tableoid <> 0) STORED
-);
-INSERT INTO gtest_tableoid VALUES (1), (2);
-SELECT * FROM gtest_tableoid;
- a | b 
----+---
- 1 | t
- 2 | t
-(2 rows)
-
 -- drop column behavior
 CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
 ALTER TABLE gtest10 DROP COLUMN b;
diff --git a/src/test/regress/sql/generated.sql b/src/test/regress/sql/generated.sql
index 63251c443a..69c334742f 100644
--- a/src/test/regress/sql/generated.sql
+++ b/src/test/regress/sql/generated.sql
@@ -17,6 +17,11 @@ CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) S
 -- references to other generated columns, including self-references
 CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STORED);
 CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STORED);
+-- a whole-row var is a self-reference on steroids
+CREATE TABLE gtest_err_2c (a int PRIMARY KEY, b int GENERATED ALWAYS AS (length(gtest_err_2c::text)) STORED);
+
+-- no system columns, either, as those aren't known when generation occurs
+CREATE TABLE gtest_err_2d (a int PRIMARY KEY, b oid GENERATED ALWAYS AS (tableoid) STORED);
 
 -- invalid reference
 CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
@@ -215,14 +220,6 @@ SELECT * FROM gtest4;
 DROP TABLE gtest4;
 DROP TYPE double_int;
 
--- using tableoid is allowed
-CREATE TABLE gtest_tableoid (
-  a int PRIMARY KEY,
-  b bool GENERATED ALWAYS AS (tableoid <> 0) STORED
-);
-INSERT INTO gtest_tableoid VALUES (1), (2);
-SELECT * FROM gtest_tableoid;
-
 -- drop column behavior
 CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
 ALTER TABLE gtest10 DROP COLUMN b;