diff --git a/install/lib/installer_base.lib.php b/install/lib/installer_base.lib.php
index f3db824cd9849ae4ad0ac4564f40a5ef89860e68..49bf4ed77b890667203295150f896ac8d3c00f93 100644
--- a/install/lib/installer_base.lib.php
+++ b/install/lib/installer_base.lib.php
@@ -2828,6 +2828,9 @@ class installer_base {
 	}
 	
 	private function loadAddonClasses($path) {
+		if(!is_dir($path)) {
+			return false;
+		}
 		$libpath = $path;
 		if(($dir = opendir($libpath))) {
 			while(false !== ($cur = readdir($dir))) {