diff --git a/library/Icingadb/Common/Macros.php b/library/Icingadb/Common/Macros.php
index 0ace2a9e1..c23420e52 100644
--- a/library/Icingadb/Common/Macros.php
+++ b/library/Icingadb/Common/Macros.php
@@ -123,6 +123,8 @@ public function resolveMacro(string $macro, $object): string
 
         if ($value instanceof DateTime) {
             $value = $value->getTimestamp();
+        } elseif (is_bool($value)) {
+            $value = $value ? 'y' : 'n';
         }
 
         return $value ?? $macro;