diff --git a/src/JsonSchema/Constraints/EnumConstraint.php b/src/JsonSchema/Constraints/EnumConstraint.php
index df413e4f..96b9e5a3 100644
--- a/src/JsonSchema/Constraints/EnumConstraint.php
+++ b/src/JsonSchema/Constraints/EnumConstraint.php
@@ -41,6 +41,6 @@ public function check($element, $schema = null, $path = null, $i = null)
             }
         }
 
-        $this->addError($path, "Does not have a value in the enumeration " . print_r($schema->enum, true), 'enum', array('enum' => $schema->enum,));
+        $this->addError($path, "Does not have a value in the enumeration " . json_encode($schema->enum), 'enum', array('enum' => $schema->enum,));
     }
 }