diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index b7ad51bdc3..7cae7dc853 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -18134,8 +18134,8 @@ AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
 
 		/*
 		 * Scan the list of existing indexes in the partition-to-be, and mark
-		 * the first matching, unattached one we find, if any, as partition of
-		 * the parent index.  If we find one, we're done.
+		 * the first matching, valid, unattached one we find, if any, as
+		 * partition of the parent index.  If we find one, we're done.
 		 */
 		for (i = 0; i < list_length(attachRelIdxs); i++)
 		{
@@ -18146,6 +18146,10 @@ AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
 			if (attachrelIdxRels[i]->rd_rel->relispartition)
 				continue;
 
+			/* If this index is invalid, can't use it */
+			if (!attachrelIdxRels[i]->rd_index->indisvalid)
+				continue;
+
 			if (CompareIndexInfo(attachInfos[i], info,
 								 attachrelIdxRels[i]->rd_indcollation,
 								 idxRel->rd_indcollation,
diff --git a/src/test/regress/expected/indexing.out b/src/test/regress/expected/indexing.out
index 1bdd430f06..64edc16a61 100644
--- a/src/test/regress/expected/indexing.out
+++ b/src/test/regress/expected/indexing.out
@@ -1421,3 +1421,33 @@ Indexes:
     "parted_index_col_drop11_b_idx" btree (b)
 
 drop table parted_index_col_drop;
+-- Check that invalid indexes are not selected when attaching a partition.
+create table parted_inval_tab (a int) partition by range (a);
+create index parted_inval_idx on parted_inval_tab (a);
+create table parted_inval_tab_1 (a int) partition by range (a);
+create table parted_inval_tab_1_1 partition of parted_inval_tab_1
+  for values from (0) to (10);
+create table parted_inval_tab_1_2 partition of parted_inval_tab_1
+  for values from (10) to (20);
+-- this creates an invalid index.
+create index parted_inval_ixd_1 on only parted_inval_tab_1 (a);
+-- this creates new indexes for all the partitions of parted_inval_tab_1,
+-- discarding the invalid index created previously as what is chosen.
+alter table parted_inval_tab attach partition parted_inval_tab_1
+  for values from (1) to (100);
+select indexrelid::regclass, indisvalid,
+       indrelid::regclass, inhparent::regclass
+  from pg_index idx left join
+       pg_inherits inh on (idx.indexrelid = inh.inhrelid)
+  where indexrelid::regclass::text like 'parted_inval%'
+  order by indexrelid::regclass::text collate "C";
+         indexrelid         | indisvalid |       indrelid       |        inhparent         
+----------------------------+------------+----------------------+--------------------------
+ parted_inval_idx           | t          | parted_inval_tab     | 
+ parted_inval_ixd_1         | f          | parted_inval_tab_1   | 
+ parted_inval_tab_1_1_a_idx | t          | parted_inval_tab_1_1 | parted_inval_tab_1_a_idx
+ parted_inval_tab_1_2_a_idx | t          | parted_inval_tab_1_2 | parted_inval_tab_1_a_idx
+ parted_inval_tab_1_a_idx   | t          | parted_inval_tab_1   | parted_inval_idx
+(5 rows)
+
+drop table parted_inval_tab;
diff --git a/src/test/regress/sql/indexing.sql b/src/test/regress/sql/indexing.sql
index 429120e710..e0b4e13037 100644
--- a/src/test/regress/sql/indexing.sql
+++ b/src/test/regress/sql/indexing.sql
@@ -760,3 +760,25 @@ alter table parted_index_col_drop drop column c;
 \d parted_index_col_drop2
 \d parted_index_col_drop11
 drop table parted_index_col_drop;
+
+-- Check that invalid indexes are not selected when attaching a partition.
+create table parted_inval_tab (a int) partition by range (a);
+create index parted_inval_idx on parted_inval_tab (a);
+create table parted_inval_tab_1 (a int) partition by range (a);
+create table parted_inval_tab_1_1 partition of parted_inval_tab_1
+  for values from (0) to (10);
+create table parted_inval_tab_1_2 partition of parted_inval_tab_1
+  for values from (10) to (20);
+-- this creates an invalid index.
+create index parted_inval_ixd_1 on only parted_inval_tab_1 (a);
+-- this creates new indexes for all the partitions of parted_inval_tab_1,
+-- discarding the invalid index created previously as what is chosen.
+alter table parted_inval_tab attach partition parted_inval_tab_1
+  for values from (1) to (100);
+select indexrelid::regclass, indisvalid,
+       indrelid::regclass, inhparent::regclass
+  from pg_index idx left join
+       pg_inherits inh on (idx.indexrelid = inh.inhrelid)
+  where indexrelid::regclass::text like 'parted_inval%'
+  order by indexrelid::regclass::text collate "C";
+drop table parted_inval_tab;