diff --git a/tests/phpunit/includes/testcase.php b/tests/phpunit/includes/testcase.php
index 9b33079f5f..e660e958c1 100644
--- a/tests/phpunit/includes/testcase.php
+++ b/tests/phpunit/includes/testcase.php
@@ -14,6 +14,8 @@ class WP_UnitTestCase extends PHPUnit_Framework_TestCase {
 	protected static $hooks_saved = array();
 	protected static $ignore_files;
 
+	protected $db_version;
+
 	/**
 	 * @var WP_UnitTest_Factory
 	 */
@@ -64,8 +66,8 @@ class WP_UnitTestCase extends PHPUnit_Framework_TestCase {
 		 *
 		 * See #31130.
 		 */
+		$this->db_version = get_option( 'db_version' );
 		if ( is_multisite() ) {
-			$this->db_version = get_option( 'db_version' );
 			add_filter( 'pre_option_db_version', array( $this, 'db_version' ) );
 		}
 	}
diff --git a/tests/phpunit/tests/term/wpInsertTerm.php b/tests/phpunit/tests/term/wpInsertTerm.php
index 660872c14d..09b0ea2089 100644
--- a/tests/phpunit/tests/term/wpInsertTerm.php
+++ b/tests/phpunit/tests/term/wpInsertTerm.php
@@ -469,8 +469,14 @@ class Tests_Term_WpInsertTerm extends WP_UnitTestCase {
 	 */
 	public function test_wp_insert_term_duplicate_slug_different_taxonomy_before_410_schema_change() {
 
-		$_db_version = $this->db_version;
-		$this->db_version = 30055;
+		// See #31130.
+		$old_db_version = 30055;
+		if ( is_multisite() ) {
+			$_db_version = $this->db_version;
+			$this->db_version = $old_db_version;
+		} else {
+			update_option( 'db_version', $old_db_version );
+		}
 
 		register_taxonomy( 'wptests_tax', 'post' );
 		register_taxonomy( 'wptests_tax_2', 'post' );
@@ -497,7 +503,10 @@ class Tests_Term_WpInsertTerm extends WP_UnitTestCase {
 		$this->assertSame( 'foo-2', $new_term->slug );
 		$this->assertNotEquals( $new_term->term_id, $term->term_id );
 
-		$this->db_version = $_db_version;
+		if ( is_multisite() ) {
+			$this->db_version = $_db_version;
+		}
+
 		_unregister_taxonomy( 'wptests_tax', 'post' );
 	}