diff --git a/install/update.php b/install/update.php
index 76d0fc3dea..8183d3aafd 100644
--- a/install/update.php
+++ b/install/update.php
@@ -396,6 +396,7 @@
 
 function incrementVersion($_version) {
 	$version = explode('.', $_version);
+	if (!isset($version[2])) $version[2] = 0;
 	if ($version[2] < 100) {
 		$version[2]++;
 	} else {