diff --git a/src/Collection/Collection.php b/src/Collection/Collection.php
index f0dcf7d3248..c7eabe4a721 100644
--- a/src/Collection/Collection.php
+++ b/src/Collection/Collection.php
@@ -41,7 +41,7 @@ public function __construct($items) {
 		}
 
 		if (!($items instanceof \Traversable)) {
-			$msg = 'Only array or \Traversable are allowed for Collection';
+			$msg = 'Only an array or \Traversable is allowed for Collection';
 			throw new InvalidArgumentException($msg);
 		}