Index: src/wp-includes/class-wp-user.php
===================================================================
--- src/wp-includes/class-wp-user.php	(revision 34455)
+++ src/wp-includes/class-wp-user.php	(working copy)
@@ -348,6 +348,14 @@
 			$key = 'ID';
 		}
 
+		$unset_blacklist = array(
+			'ID' => 0,
+		);
+		if ( array_key_exists( $key, $unset_blacklist ) ) {
+			$this->data->$key = $unset_blacklist[ $key ];
+			return;
+		}
+
 		if ( isset( $this->data->$key ) ) {
 			unset( $this->data->$key );
 		}