diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index d545bbce8a..d3a0dece5a 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -53,6 +53,7 @@
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "utils/builtins.h"
+#include "utils/datum.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 
@@ -254,9 +255,6 @@ ExecComputeStoredGenerated(EState *estate, TupleTableSlot *slot)
 	MemoryContext oldContext;
 	Datum	   *values;
 	bool	   *nulls;
-	bool	   *replaces;
-	HeapTuple	oldtuple, newtuple;
-	bool		should_free;
 
 	Assert(tupdesc->constr && tupdesc->constr->has_generated_stored);
 
@@ -294,11 +292,15 @@ ExecComputeStoredGenerated(EState *estate, TupleTableSlot *slot)
 
 	values = palloc(sizeof(*values) * natts);
 	nulls = palloc(sizeof(*nulls) * natts);
-	replaces = palloc0(sizeof(*replaces) * natts);
+
+	slot_getallattrs(slot);
+	memcpy(nulls, slot->tts_isnull, sizeof(*nulls) * natts);
 
 	for (int i = 0; i < natts; i++)
 	{
-		if (TupleDescAttr(tupdesc, i)->attgenerated == ATTRIBUTE_GENERATED_STORED)
+		Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
+
+		if (attr->attgenerated == ATTRIBUTE_GENERATED_STORED)
 		{
 			ExprContext *econtext;
 			Datum		val;
@@ -311,20 +313,19 @@ ExecComputeStoredGenerated(EState *estate, TupleTableSlot *slot)
 
 			values[i] = val;
 			nulls[i] = isnull;
-			replaces[i] = true;
+		}
+		else
+		{
+			if (!nulls[i])
+				values[i] = datumCopy(slot->tts_values[i], attr->attbyval, attr->attlen);
 		}
 	}
 
-	oldtuple = ExecFetchSlotHeapTuple(slot, true, &should_free);
-	newtuple = heap_modify_tuple(oldtuple, tupdesc, values, nulls, replaces);
-	/*
-	 * The tuple will be freed by way of the memory context - the slot might
-	 * only be cleared after the context is reset, and we'd thus potentially
-	 * double free.
-	 */
-	ExecForceStoreHeapTuple(newtuple, slot, false);
-	if (should_free)
-		heap_freetuple(oldtuple);
+	ExecClearTuple(slot);
+	memcpy(slot->tts_values, values, sizeof(*values) * natts);
+	memcpy(slot->tts_isnull, nulls, sizeof(*nulls) * natts);
+	ExecStoreVirtualTuple(slot);
+	ExecMaterializeSlot(slot);
 
 	MemoryContextSwitchTo(oldContext);
 }
diff --git a/src/test/regress/expected/generated.out b/src/test/regress/expected/generated.out
index d4ed3f7ae1..f62c93f468 100644
--- a/src/test/regress/expected/generated.out
+++ b/src/test/regress/expected/generated.out
@@ -226,15 +226,16 @@ NOTICE:  merging multiple inherited definitions of column "b"
 ERROR:  inherited column "b" has a generation conflict
 DROP TABLE gtesty;
 -- test stored update
-CREATE TABLE gtest3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 3) STORED);
-INSERT INTO gtest3 (a) VALUES (1), (2), (3);
+CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
+INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
 SELECT * FROM gtest3 ORDER BY a;
  a | b 
 ---+---
  1 | 3
  2 | 6
  3 | 9
-(3 rows)
+   |  
+(4 rows)
 
 UPDATE gtest3 SET a = 22 WHERE a = 2;
 SELECT * FROM gtest3 ORDER BY a;
@@ -243,7 +244,29 @@ SELECT * FROM gtest3 ORDER BY a;
   1 |  3
   3 |  9
  22 | 66
-(3 rows)
+    |   
+(4 rows)
+
+CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
+INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
+SELECT * FROM gtest3a ORDER BY a;
+ a |  b  
+---+-----
+ a | a+a
+ b | b+b
+ c | c+c
+   | 
+(4 rows)
+
+UPDATE gtest3a SET a = 'bb' WHERE a = 'b';
+SELECT * FROM gtest3a ORDER BY a;
+ a  |   b   
+----+-------
+ a  | a+a
+ bb | bb+bb
+ c  | c+c
+    | 
+(4 rows)
 
 -- COPY
 TRUNCATE gtest1;
diff --git a/src/test/regress/sql/generated.sql b/src/test/regress/sql/generated.sql
index da11b8c9b8..6a56ae260f 100644
--- a/src/test/regress/sql/generated.sql
+++ b/src/test/regress/sql/generated.sql
@@ -95,12 +95,18 @@ CREATE TABLE gtest1_2 () INHERITS (gtest1, gtesty);  -- error
 DROP TABLE gtesty;
 
 -- test stored update
-CREATE TABLE gtest3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 3) STORED);
-INSERT INTO gtest3 (a) VALUES (1), (2), (3);
+CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
+INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
 SELECT * FROM gtest3 ORDER BY a;
 UPDATE gtest3 SET a = 22 WHERE a = 2;
 SELECT * FROM gtest3 ORDER BY a;
 
+CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
+INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
+SELECT * FROM gtest3a ORDER BY a;
+UPDATE gtest3a SET a = 'bb' WHERE a = 'b';
+SELECT * FROM gtest3a ORDER BY a;
+
 -- COPY
 TRUNCATE gtest1;
 INSERT INTO gtest1 (a) VALUES (1), (2);