diff --git a/php/class-wp-cli.php b/php/class-wp-cli.php
index 4ad1a352..af5542e9 100644
--- a/php/class-wp-cli.php
+++ b/php/class-wp-cli.php
@@ -472,6 +472,9 @@ public function swap_coauthors( $args, $assoc_args ) {
 						}
 					}
 
+					// Add the 'to' author on
+					$coauthors[] = $to_userlogin;
+
 					// By not passing $append = false as the 3rd param, we replace all existing coauthors
 					$coauthors_plus->add_coauthors( $post->ID, $coauthors, false );