diff --git a/library/Icinga/Web/View/AppHealth.php b/library/Icinga/Web/View/AppHealth.php
index fe1c56cbe..c66ca05fd 100644
--- a/library/Icinga/Web/View/AppHealth.php
+++ b/library/Icinga/Web/View/AppHealth.php
@@ -72,7 +72,7 @@ class AppHealth extends Table
     protected function getStateText($state)
     {
         if ($state === null) {
-            $state = t('UNKOWN');
+            $state = t('UNKNOWN');
         }
 
         switch ($state) {