diff --git a/src/Assert.php b/src/Assert.php
index a0cd0154..8b59d660 100644
--- a/src/Assert.php
+++ b/src/Assert.php
@@ -38,13 +38,13 @@ class Assert
 	public function isNull($actual)
 	{
 		if ($actual !== null)
-			$this->fail('Assertion failed. Expected: NULL, got: "' . $this->dumpVar(actual) . '"');
+			$this->fail('Assertion failed. Expected: NULL, got: "' . $this->dumpVar($actual) . '"');
 	}
 
 	public function isNotNull($actual)
 	{
 		if ($actual === null)
-			$this->fail('Assertion failed. Expected: not NULL, got: "' . $this->dumpVar(actual) . '"');
+			$this->fail('Assertion failed. Expected: not NULL, got: "' . $this->dumpVar($actual) . '"');
 	}
 
 	public function isTrue($actual)