diff --git a/Math/Number/OpperationInterface.php b/Math/Number/OpperationInterface.php
index d662d1d9d..93031d2de 100644
--- a/Math/Number/OpperationInterface.php
+++ b/Math/Number/OpperationInterface.php
@@ -98,5 +98,5 @@ interface OperationInterface
      * @since  1.0.0
      * @author Dennis Eichhorn <d.eichhorn@oms.com>
      */
-    public function abs($x);
+    public function abs();
 }
\ No newline at end of file