diff --git a/src/wp-includes/taxonomy.php b/src/wp-includes/taxonomy.php
index 15ccacb767..698a0699cc 100644
--- a/src/wp-includes/taxonomy.php
+++ b/src/wp-includes/taxonomy.php
@@ -580,11 +580,6 @@ function unregister_taxonomy( $taxonomy ) {
 	$taxonomy_object->remove_rewrite_rules();
 	$taxonomy_object->remove_hooks();
 
-	// Remove custom taxonomy default term option.
-	if ( ! empty( $taxonomy_object->default_term ) ) {
-		delete_option( 'default_term_' . $taxonomy_object->name );
-	}
-
 	// Remove the taxonomy.
 	unset( $wp_taxonomies[ $taxonomy ] );
 
diff --git a/tests/phpunit/tests/taxonomy.php b/tests/phpunit/tests/taxonomy.php
index 6b7e88007b..69dc1a8180 100644
--- a/tests/phpunit/tests/taxonomy.php
+++ b/tests/phpunit/tests/taxonomy.php
@@ -1044,9 +1044,6 @@ class Tests_Taxonomy extends WP_UnitTestCase {
 		wp_set_object_terms( $post_id, array(), $tax );
 		$term = wp_get_post_terms( $post_id, $tax );
 		$this->assertSame( array(), $term );
-
-		unregister_taxonomy( $tax );
-		$this->assertSame( get_option( 'default_term_' . $tax ), false );
 	}
 
 	/**