diff --git a/phpseclib/File/ANSI.php b/phpseclib/File/ANSI.php
index 0cbed1731..ac030df7f 100644
--- a/phpseclib/File/ANSI.php
+++ b/phpseclib/File/ANSI.php
@@ -299,7 +299,7 @@ function appendString($source)
                     case "\x1B[K": // Clear screen from cursor right
                         $this->screen[$this->y] = substr($this->screen[$this->y], 0, $this->x);
 
-                        array_splice($this->attrs[$this->y], $this->x + 1, $this->max_x - $this->x, array_fill($this->x, $this->max_x - $this->x - 1, $this->base_attr_cell));
+                        array_splice($this->attrs[$this->y], $this->x + 1, $this->max_x - $this->x, array_fill($this->x, $this->max_x - ($this->x - 1), $this->base_attr_cell));
                         break;
                     case "\x1B[2K": // Clear entire line
                         $this->screen[$this->y] = str_repeat(' ', $this->x);