diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index a602b46..4303697 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -226,7 +226,7 @@
 				}
 				
 				// Is there a file name?
-				if ( ! preg_match("#[\.jpg|\.jpeg|\.gif|\.png]$#i", $full_dest_path))
+				if ( ! preg_match("#\.(jpg|jpeg|gif|png)$#i", $full_dest_path))
 				{
 					$this->dest_folder = $full_dest_path.'/';
 					$this->dest_image = $this->source_image;
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index e15cfc4..1199149 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -85,6 +85,7 @@
 <ul>
 	<li>Amended fixes for bug (#3419) with parsing DSN database connections.</li>
 	<li>Fixed a syntax error in upload_lang.php</li>
+	<li>Fixed a bug (#4542) with a regular expression in the Image library</li>
 </ul>
 
 <h2>Version 1.6.2</h2>