diff --git a/library/Icinga/Application/Modules/Module.php b/library/Icinga/Application/Modules/Module.php
index 12a8e3f67..7519cf0ca 100644
--- a/library/Icinga/Application/Modules/Module.php
+++ b/library/Icinga/Application/Modules/Module.php
@@ -1003,11 +1003,13 @@ class Module
 
                             $parts = preg_split('/,\s+/', $val);
                             foreach ($parts as $i => $part) {
-                                if (strpos($part, '|') !== false) {
+                                if (strpos($part, ' | ') !== false) {
                                     $orParts = array_map('trim', explode('|', $part));
                                     foreach ($orParts as $orPart) {
                                         if (preg_match('/^([\w\-\/]+)\s+\((.+)\)$/', $orPart, $m)) {
                                             $metadata->{$key}['|' . $i][$m[1]] = $m[2];
+                                        } elseif (preg_match('/^([\w\-\/]+)$/', $orPart, $m)) {
+                                            $metadata->{$key}['|' . $i][$m[1]] = null;
                                         }
                                     }
                                 } elseif (preg_match('/^([\w\-\/]+)\s+\((.+)\)$/', $part, $m)) {