diff --git a/core/modules/taxonomy/taxonomy.install b/core/modules/taxonomy/taxonomy.install
index 61ac2f5..179aaeb 100644
--- a/core/modules/taxonomy/taxonomy.install
+++ b/core/modules/taxonomy/taxonomy.install
@@ -377,6 +377,9 @@ function taxonomy_update_8007() {
         db_add_index($table_name, $field->id() . '_target_id', array($field->id() . '_target_id'));
       }
 
+      // Update the indexes in field config as well.
+      $field_config->set('indexes', array('target_id' => array('target_id')));
+      $field_config->save();
     }
   }
 }
diff --git a/core/profiles/standard/config/field.field.field_tags.yml b/core/profiles/standard/config/field.field.field_tags.yml
index 21f25ce..e0f6952 100644
--- a/core/profiles/standard/config/field.field.field_tags.yml
+++ b/core/profiles/standard/config/field.field.field_tags.yml
@@ -16,6 +16,8 @@ locked: '0'
 cardinality: '-1'
 translatable: '0'
 entity_types: {  }
-indexes: { }
+indexes:
+  target_id:
+    - target_id
 status: 1
 langcode: und