diff --git a/library/Icinga/Data/Filter/Filter.php b/library/Icinga/Data/Filter/Filter.php
index 99b0290f1..0688d2cc0 100644
--- a/library/Icinga/Data/Filter/Filter.php
+++ b/library/Icinga/Data/Filter/Filter.php
@@ -22,6 +22,10 @@ abstract class Filter
         return $this;
     }
 
+    abstract public function isExpression();
+
+    abstract public function isChain();
+
     abstract function toQueryString();
 
     public function getUrlParams()
diff --git a/library/Icinga/Data/Filter/FilterChain.php b/library/Icinga/Data/Filter/FilterChain.php
index 9d32252fe..c7697b7ad 100644
--- a/library/Icinga/Data/Filter/FilterChain.php
+++ b/library/Icinga/Data/Filter/FilterChain.php
@@ -166,6 +166,16 @@ abstract class FilterChain extends Filter
         }
     }
 
+    public function isExpression()
+    {
+        return false;
+    }
+
+    public function isChain()
+    {
+        return true;
+    }
+
     public function isEmpty()
     {
         return empty($this->filters);
diff --git a/library/Icinga/Data/Filter/FilterExpression.php b/library/Icinga/Data/Filter/FilterExpression.php
index 8378b5ae3..8f78d6a87 100644
--- a/library/Icinga/Data/Filter/FilterExpression.php
+++ b/library/Icinga/Data/Filter/FilterExpression.php
@@ -19,6 +19,16 @@ class FilterExpression extends Filter
         $this->expression = $expression;
     }
 
+    public function isExpression()
+    {
+        return true;
+    }
+
+    public function isChain()
+    {
+        return false;
+    }
+
     public function isEmpty()
     {
         return false;