diff --git a/src/wp-includes/taxonomy.php b/src/wp-includes/taxonomy.php
index 8cbef3c718..9865f42be7 100644
--- a/src/wp-includes/taxonomy.php
+++ b/src/wp-includes/taxonomy.php
@@ -390,6 +390,9 @@ function register_taxonomy( $taxonomy, $object_type, $args = array() ) {
 		else
 			$args['query_var'] = sanitize_title_with_dashes( $args['query_var'] );
 		$wp->add_query_var( $args['query_var'] );
+	} else {
+		// Force query_var to false for non-public taxonomies.
+		$args['query_var'] = false;
 	}
 
 	if ( false !== $args['rewrite'] && ( is_admin() || '' != get_option( 'permalink_structure' ) ) ) {
diff --git a/tests/phpunit/tests/taxonomy.php b/tests/phpunit/tests/taxonomy.php
index 2063bbe333..0cf65169e1 100644
--- a/tests/phpunit/tests/taxonomy.php
+++ b/tests/phpunit/tests/taxonomy.php
@@ -517,4 +517,17 @@ class Tests_Taxonomy extends WP_UnitTestCase {
 
 		$this->assertFalse( is_tax( 'wptests_tax' ) );
 	}
+
+	/**
+	 * @ticket 35089
+	 */
+	public function test_query_var_should_be_forced_to_false_for_non_public_taxonomy() {
+		register_taxonomy( 'wptests_tax', 'post', array(
+			'public' => false,
+			'query_var' => true,
+		) );
+
+		$tax = get_taxonomy( 'wptests_tax' );
+		$this->assertFalse( $tax->query_var );
+	}
 }