diff --git a/library/Director/Data/Db/DbDataFormatter.php b/library/Director/Data/Db/DbDataFormatter.php
index d6e4eeb5..e06af69b 100644
--- a/library/Director/Data/Db/DbDataFormatter.php
+++ b/library/Director/Data/Db/DbDataFormatter.php
@@ -6,7 +6,7 @@ use InvalidArgumentException;
 
 class DbDataFormatter
 {
-    public static function normalizeBoolean($value)
+    public static function normalizeBoolean($value): ?string
     {
         if ($value === 'y' || $value === '1' || $value === true || $value === 1) {
             return 'y';
@@ -23,4 +23,16 @@ class DbDataFormatter
             var_export($value, 1)
         ));
     }
+
+    public static function booleanForDbValue($value): ?bool
+    {
+        if ($value === 'y') {
+            return true;
+        }
+        if ($value === 'n') {
+            return false;
+        }
+
+        return $value; // let this fail elsewhere, if not null
+    }
 }
diff --git a/library/Director/Data/Db/DbObject.php b/library/Director/Data/Db/DbObject.php
index 6ecae8b7..9a89039c 100644
--- a/library/Director/Data/Db/DbObject.php
+++ b/library/Director/Data/Db/DbObject.php
@@ -80,6 +80,9 @@ abstract class DbObject
 
     protected $binaryProperties = [];
 
+    /* key/value!! */
+    protected $booleans = [];
+
     /**
      * Filled with object instances when prefetchAll is used
      */
@@ -346,6 +349,10 @@ abstract class DbObject
             return $this->$func($value);
         }
 
+        if ($this->propertyIsBoolean($key)) {
+            $value = DbDataFormatter::normalizeBoolean($value);
+        }
+
         if (! $this->hasProperty($key)) {
             throw new InvalidArgumentException(sprintf(
                 'Trying to set invalid key "%s"',
@@ -878,6 +885,11 @@ abstract class DbObject
         return in_array($column, $this->binaryProperties) || $this->getUuidColumn() === $column;
     }
 
+    public function propertyIsBoolean($property)
+    {
+        return array_key_exists($property, $this->booleans);
+    }
+
     /**
      * Store object to database
      *
diff --git a/library/Director/Objects/IcingaObject.php b/library/Director/Objects/IcingaObject.php
index 04ae32b1..a2b1d9b1 100644
--- a/library/Director/Objects/IcingaObject.php
+++ b/library/Director/Objects/IcingaObject.php
@@ -63,9 +63,6 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
 
     protected $type;
 
-    /* key/value!! */
-    protected $booleans = [];
-
     // Property suffixed with _id must exist
     protected $relations = [
         // property => PropertyClass
@@ -142,11 +139,6 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
         return $this->connection;
     }
 
-    public function propertyIsBoolean($property)
-    {
-        return array_key_exists($property, $this->booleans);
-    }
-
     public function propertyIsInterval($property)
     {
         return array_key_exists($property, $this->intervalProperties);
@@ -771,10 +763,6 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
             return $this;
         }
 
-        if ($this->propertyIsBoolean($key)) {
-            return parent::set($key, DbDataFormatter::normalizeBoolean($value));
-        }
-
         // e.g. zone_id
         if ($this->propertyIsRelation($key)) {
             return $this->setRelation($key, $value);
@@ -2894,7 +2882,7 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
             // TODO: Do not ship null properties based on flag?
             if (!$skipDefaults || $this->differsFromDefaultValue($k, $v)) {
                 if ($k === 'disabled' || $this->propertyIsBoolean($k)) {
-                    $props[$k] = $this->booleanForDbValue($v);
+                    $props[$k] = DbDataFormatter::booleanForDbValue($v);
                 } else {
                     $props[$k] = $v;
                 }
@@ -3005,18 +2993,6 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
         return (object) $props;
     }
 
-    protected function booleanForDbValue($value)
-    {
-        if ($value === 'y') {
-            return true;
-        }
-        if ($value === 'n') {
-            return false;
-        }
-
-        return $value; // let this fail elsewhere, if not null
-    }
-
     public function listImportNames()
     {
         if ($this->gotImports()) {
@@ -3161,7 +3137,7 @@ abstract class IcingaObject extends DbObject implements IcingaConfigRenderer
 
             if ($this->differsFromDefaultValue($k, $v)) {
                 if ($k === 'disabled' || $this->propertyIsBoolean($k)) {
-                    $props[$k] = $this->booleanForDbValue($v);
+                    $props[$k] = DbDataFormatter::booleanForDbValue($v);
                 } else {
                     $props[$k] = $v;
                 }