diff --git a/src/wp-includes/taxonomy.php b/src/wp-includes/taxonomy.php
index 2f8cef9a8c..71c422d60b 100644
--- a/src/wp-includes/taxonomy.php
+++ b/src/wp-includes/taxonomy.php
@@ -345,9 +345,9 @@ function register_taxonomy( $taxonomy, $object_type, $args = array() ) {
 	);
 	$args = wp_parse_args( $args, $defaults );
 
-	if ( strlen( $taxonomy ) > 32 ) {
-		_doing_it_wrong( __FUNCTION__, __( 'Taxonomies cannot exceed 32 characters in length' ), '4.0' );
-		return new WP_Error( 'taxonomy_too_long', __( 'Taxonomies cannot exceed 32 characters in length' ) );
+	if ( empty( $taxonomy ) || strlen( $taxonomy ) > 32 ) {
+		_doing_it_wrong( __FUNCTION__, __( 'Taxonomy names must be between 1 and 32 characters in length.' ), '4.2' );
+		return new WP_Error( 'taxonomy_length_invalid', __( 'Taxonomy names must be between 1 and 32 characters in length.' ) );
 	}
 
 	if ( false !== $args['query_var'] && ! empty( $wp ) ) {
diff --git a/tests/phpunit/tests/taxonomy.php b/tests/phpunit/tests/taxonomy.php
index dc153926b8..529b18cf74 100644
--- a/tests/phpunit/tests/taxonomy.php
+++ b/tests/phpunit/tests/taxonomy.php
@@ -153,6 +153,15 @@ class Tests_Taxonomy extends WP_UnitTestCase {
 		unset($GLOBALS['wp_taxonomies'][$tax]);
 	}
 
+	/**
+	 * @ticket 31135
+	 *
+	 * @expectedIncorrectUsage register_taxonomy
+	 */
+	function test_register_short_taxonomy() {
+		$this->assertInstanceOf( 'WP_Error', register_taxonomy( '', 'post', array() ) );
+	}
+
 	/**
 	 * @ticket 21593
 	 *