diff --git a/contrib/handle_archive/main.php b/contrib/handle_archive/main.php
index 72fa640b..0d5b1b81 100644
--- a/contrib/handle_archive/main.php
+++ b/contrib/handle_archive/main.php
@@ -41,7 +41,7 @@ class ArchiveFileHandler extends SimpleExtension {
 
 	private function supported_ext($ext) {
 		$exts = array("zip");
-		return array_contains($exts, strtolower($ext));
+		return in_array(strtolower($ext), $exts);
 	}
 
 	// copied from bulk add extension
diff --git a/contrib/handle_flash/main.php b/contrib/handle_flash/main.php
index db1b9e61..cd2671c4 100644
--- a/contrib/handle_flash/main.php
+++ b/contrib/handle_flash/main.php
@@ -41,7 +41,7 @@ class FlashFileHandler extends SimpleExtension {
 
 	private function supported_ext($ext) {
 		$exts = array("swf");
-		return array_contains($exts, strtolower($ext));
+		return in_array(strtolower($ext), $exts);
 	}
 
 	private function create_image_from_data($filename, $metadata) {
@@ -124,7 +124,7 @@ class FlashFileHandler extends SimpleExtension {
 		$fp = fopen($file, "r");
 		$head = fread($fp, 3);
 		fclose($fp);
-		if(!array_contains(array("CWS", "FWS"), $head)) return false;
+		if(!in_array($head, array("CWS", "FWS"))) return false;
 
 		return true;
 	}
diff --git a/contrib/handle_ico/main.php b/contrib/handle_ico/main.php
index 67bab3c0..678f2579 100644
--- a/contrib/handle_ico/main.php
+++ b/contrib/handle_ico/main.php
@@ -49,7 +49,7 @@ class IcoFileHandler extends SimpleExtension {
 
 	private function supported_ext($ext) {
 		$exts = array("ico", "ani", "cur");
-		return array_contains($exts, strtolower($ext));
+		return in_array(strtolower($ext), $exts);
 	}
 
 	private function create_image_from_data($filename, $metadata) {
diff --git a/contrib/handle_mp3/main.php b/contrib/handle_mp3/main.php
index 7d0715f4..dc771a93 100644
--- a/contrib/handle_mp3/main.php
+++ b/contrib/handle_mp3/main.php
@@ -37,7 +37,7 @@ class MP3FileHandler implements Extension {
 
 	private function supported_ext($ext) {
 		$exts = array("mp3");
-		return array_contains($exts, strtolower($ext));
+		return in_array(strtolower($ext), $exts);
 	}
 
 	private function create_image_from_data($filename, $metadata) {
diff --git a/contrib/handle_svg/main.php b/contrib/handle_svg/main.php
index 5ddc5cdc..741a3805 100644
--- a/contrib/handle_svg/main.php
+++ b/contrib/handle_svg/main.php
@@ -63,7 +63,7 @@ class SVGFileHandler implements Extension {
 
 	private function supported_ext($ext) {
 		$exts = array("svg");
-		return array_contains($exts, strtolower($ext));
+		return in_array(strtolower($ext), $exts);
 	}
 
 	private function create_image_from_data($filename, $metadata) {
diff --git a/core/util.inc.php b/core/util.inc.php
index e957cfef..d7116c44 100644
--- a/core/util.inc.php
+++ b/core/util.inc.php
@@ -256,15 +256,6 @@ function array_add($array, $element) {
 	return $array;
 }
 
-function array_contains($array, $target) {
-	foreach($array as $element) {
-		if($target == $element) {
-			return true;
-		}
-	}
-	return false;
-}
-
 // case insensetive uniqueness
 function array_iunique($array) {
 	$ok = array();
diff --git a/ext/handle_pixel/main.php b/ext/handle_pixel/main.php
index e6430218..ab6b45a1 100644
--- a/ext/handle_pixel/main.php
+++ b/ext/handle_pixel/main.php
@@ -37,7 +37,7 @@ class PixelFileHandler implements Extension {
 
 	private function supported_ext($ext) {
 		$exts = array("jpg", "jpeg", "gif", "png");
-		return array_contains($exts, strtolower($ext));
+		return in_array(strtolower($ext), $exts);
 	}
 
 	private function create_image_from_data($filename, $metadata) {
@@ -66,7 +66,7 @@ class PixelFileHandler implements Extension {
 		if(!file_exists($file)) return false;
 		$info = getimagesize($file);
 		if(is_null($info)) return false;
-		if(array_contains($valid, $info[2])) return true;
+		if(in_array($info[2], $valid)) return true;
 		return false;
 	}
 
diff --git a/index.php b/index.php
index 538688c6..646e48be 100644
--- a/index.php
+++ b/index.php
@@ -45,7 +45,7 @@ try {
 		$m = array();
 		foreach($custom_themelets as $filename) {
 			if(preg_match("/themes\/$_theme\/(.*)\.theme\.php/",$filename,$m)
-					&& array_contains($themelets, "ext/{$m[1]}/theme.php")) {
+					&& in_array("ext/{$m[1]}/theme.php", $themelets)) {
 				require_once $filename;
 			}
 		}