diff --git a/mysql-test/main/vector_innodb.result b/mysql-test/main/vector_innodb.result
index f26bebb69aa..9952b5e1f69 100644
--- a/mysql-test/main/vector_innodb.result
+++ b/mysql-test/main/vector_innodb.result
@@ -103,3 +103,17 @@ select pk,hex(v) from t;
 pk	hex(v)
 1	B047263C9F87233FCFD27E3EAE493E3F0329F43E
 drop table t;
+#
+# MDEV-35039 Number of indexes inside InnoDB differs from that defined in MariaDB after altering table with vector key
+#
+create table t (v blob not null, vector index (v)) row_format=compressed engine=innodb;
+alter table t add f int;
+insert into t values (x'00000000',1);
+show create table t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `v` blob NOT NULL,
+  `f` int(11) DEFAULT NULL,
+  VECTOR KEY `v` (`v`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci ROW_FORMAT=COMPRESSED
+drop table t;
diff --git a/mysql-test/main/vector_innodb.test b/mysql-test/main/vector_innodb.test
index 5489627b152..9d77bde0d3c 100644
--- a/mysql-test/main/vector_innodb.test
+++ b/mysql-test/main/vector_innodb.test
@@ -87,3 +87,12 @@ create table t (pk int primary key, v varbinary(1024) not null, vector key(v)) e
 insert into t values (1, x'B047263C9F87233fcfd27e3eae493e3f0329f43e');
 select pk,hex(v) from t;
 drop table t;
+
+--echo #
+--echo # MDEV-35039 Number of indexes inside InnoDB differs from that defined in MariaDB after altering table with vector key
+--echo #
+create table t (v blob not null, vector index (v)) row_format=compressed engine=innodb;
+alter table t add f int;
+insert into t values (x'00000000',1);
+show create table t;
+drop table t;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index dec223a1813..2ffff612c45 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -7319,10 +7319,17 @@ static bool fill_alter_inplace_info(THD *thd, TABLE *table,
     Adding/dropping any indexes in a table that already has high-level indexes
     may shift high-level indexes numbers. And thus require high-level indexes
     rename, which algorithm=inplace (storage engines) shouldn't do.
+
+    If we aren't adding/dropping indexes, ha_alter_info->key_count is
+    table->s->total_keys, but must be table->s->keys to not confuse the engine.
   */
-  if (table->s->hlindexes() &&
-      (ha_alter_info->index_drop_count || ha_alter_info->index_add_count))
-    ha_alter_info->inplace_supported= HA_ALTER_INPLACE_NOT_SUPPORTED;
+  if (table->s->hlindexes())
+  {
+    if (ha_alter_info->index_drop_count || ha_alter_info->index_add_count)
+      ha_alter_info->inplace_supported= HA_ALTER_INPLACE_NOT_SUPPORTED;
+    else
+      ha_alter_info->key_count= table->s->keys;
+  }
 
   DBUG_PRINT("exit", ("handler_flags: %llu", ha_alter_info->handler_flags));
   DBUG_RETURN(false);