diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 18e3253..ca1d747 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -398,7 +398,7 @@
// Allowed rotation values
$degs = array(90, 180, 270, 'vrt', 'hor');
- if ($this->rotation_angle == '' OR ! in_array($this->rotation_angle, $degs))
+ if ($this->rotation_angle == '' OR ! in_array($this->rotation_angle, $degs, TRUE))
{
$this->set_error('imglib_rotation_angle_required');
return FALSE;