diff --git a/core/imageboard.pack.php b/core/imageboard.pack.php
index 02f5f221..a11c1620 100644
--- a/core/imageboard.pack.php
+++ b/core/imageboard.pack.php
@@ -387,7 +387,7 @@ class Image {
 	 * @retval string
 	 */
 	public function get_mime_type() {
-		return getMimeType($this->get_image_filename());
+		return getMimeType($this->get_image_filename(), $this->get_ext());
 	}
 
 	/**
diff --git a/core/util.inc.php b/core/util.inc.php
index b1670b7e..a18b1923 100644
--- a/core/util.inc.php
+++ b/core/util.inc.php
@@ -489,7 +489,7 @@ function captcha_check() {
 * @param string &$file File path
 * @return string
 */
-function getMimeType($file) {
+function getMimeType($file, $ext="") {
 	$type = false;
 	// Fileinfo documentation says fileinfo_open() will use the
 	// MAGIC env var for the magic file
@@ -527,7 +527,6 @@ function getMimeType($file) {
 		'avi' => 'video/x-msvideo', 'mpg' => 'video/mpeg', 'mpeg' => 'video/mpeg',
 		'mov' => 'video/quicktime', 'flv' => 'video/x-flv', 'php' => 'text/x-php'
 	);
-	$ext = strtolower(pathInfo($file, PATHINFO_EXTENSION));
 	return isset($exts[$ext]) ? $exts[$ext] : 'application/octet-stream';
 }