diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index a9235210f7..e8c85832d3 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -329,9 +329,8 @@ function sanitize_title($title, $fallback_title = '') {
 	$title = strip_tags($title);
 	$title = apply_filters('sanitize_title', $title);
 
-	if (empty($title)) {
+	if ( '' === $title || false === $title )
 		$title = $fallback_title;
-	}
 
 	return $title;
 }
diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index 7179c60d57..6131f6fba0 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -707,7 +707,7 @@ function is_term($term, $taxonomy = '') {
 			return 0;
 		$where = $wpdb->prepare( "t.term_id = %d", $term );
 	} else {
-		if ( ! $term = sanitize_title($term) )
+		if ( '' === $term = sanitize_title($term) )
 			return 0;
 		$where = $wpdb->prepare( "t.slug = %s", $term );
 	}