diff --git a/src/wp-includes/link-template.php b/src/wp-includes/link-template.php
index 0d06a3f9ca..164bcd905c 100644
--- a/src/wp-includes/link-template.php
+++ b/src/wp-includes/link-template.php
@@ -191,7 +191,9 @@ function get_permalink( $post = 0, $leavename = false ) {
 			// having to assign it explicitly
 			if ( empty($category) ) {
 				$default_category = get_term( get_option( 'default_category' ), 'category' );
-				$category = is_wp_error( $default_category ) ? '' : $default_category->slug;
+				if ( $default_category && ! is_wp_error( $default_category ) ) {
+					$category = $default_category->slug;
+				}
 			}
 		}