diff --git a/engine/skin.php b/engine/skin.php
index 2ba35f6..ca763f3 100644
--- a/engine/skin.php
+++ b/engine/skin.php
@@ -166,7 +166,7 @@ class SkinContext {
         }
         $given_count = count($arguments)+1;
         assert($given_count >= $fparams_required_count && $given_count <= count($fparams),
-            "$fn: invalid number of arguments (function has ".$fparams_required_count." required arguments".(count($fparams) != $fparams_required_count ? ' and '.count($fparams).' total argumments' : '').", received ".(count($arguments) + 1).")");
+            "$fn: invalid number of arguments (function has ".$fparams_required_count." required arguments".(count($fparams) != $fparams_required_count ? ' and '.count($fparams).' total arguments' : '').", received ".(count($arguments) + 1).")");
 
         foreach ($fparams as $n => $param) {
             if ($n == 0)