diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index 64ac3063c61..0087585b2c4 100644
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -1636,8 +1636,6 @@ BeginCopyFrom(ParseState *pstate,
 
 	if (cstate->opts.on_error == COPY_ON_ERROR_SET_NULL)
 	{
-		int			attr_count = list_length(cstate->attnumlist);
-
 		/*
 		 * When data type conversion fails and ON_ERROR is SET_NULL, we need
 		 * ensure that the input column allow null values.  ExecConstraints()
@@ -1646,15 +1644,13 @@ BeginCopyFrom(ParseState *pstate,
 		 * check must be performed during the initial string-to-datum
 		 * conversion (see CopyFromTextLikeOneRow()).
 		 */
-		cstate->domain_with_constraint = palloc0_array(bool, attr_count);
+		cstate->domain_with_constraint = palloc0_array(bool, num_phys_attrs);
 
 		foreach_int(attno, cstate->attnumlist)
 		{
-			int			i = foreach_current_index(attno);
-
 			Form_pg_attribute att = TupleDescAttr(tupDesc, attno - 1);
 
-			cstate->domain_with_constraint[i] = DomainHasConstraints(att->atttypid, NULL);
+			cstate->domain_with_constraint[attno - 1] = DomainHasConstraints(att->atttypid, NULL);
 		}
 	}
 
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 7600e5239d2..919eabd5f78 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -805,6 +805,10 @@ COPY t_on_error_null FROM STDIN WITH (on_error set_null); -- fail
 ERROR:  domain d_int_not_null does not allow null values
 DETAIL:  ON_ERROR SET_NULL cannot be applied because column "a" (domain d_int_not_null) does not accept null values.
 CONTEXT:  COPY t_on_error_null, line 1, column a: null input
+COPY t_on_error_null(c, a) FROM STDIN WITH (on_error set_null); -- fail
+ERROR:  domain d_int_not_null does not allow null values
+DETAIL:  ON_ERROR SET_NULL cannot be applied because column "a" (domain d_int_not_null) does not accept null values.
+CONTEXT:  COPY t_on_error_null, line 1, column a: null input
 COPY t_on_error_null FROM STDIN WITH (on_error set_null); -- fail
 ERROR:  domain d_int_not_null does not allow null values
 DETAIL:  ON_ERROR SET_NULL cannot be applied because column "a" (domain d_int_not_null) does not accept null values.
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index e0810109473..f853499021d 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -555,6 +555,10 @@ COPY t_on_error_null FROM STDIN WITH (on_error set_null); -- fail
 \N	11	13
 \.
 
+COPY t_on_error_null(c, a) FROM STDIN WITH (on_error set_null); -- fail
+11	\N
+\.
+
 COPY t_on_error_null FROM STDIN WITH (on_error set_null); -- fail
 ss	11	14
 \.