diff --git a/tests/forms/MemberDatetimeOptionsetFieldTest.php b/tests/forms/MemberDatetimeOptionsetFieldTest.php
index b2a381651..608ddf3b6 100644
--- a/tests/forms/MemberDatetimeOptionsetFieldTest.php
+++ b/tests/forms/MemberDatetimeOptionsetFieldTest.php
@@ -83,11 +83,11 @@ class MemberDatetimeOptionsetFieldTest extends SapphireTest {
 
 	function testDateFormValid() {
 		$field = new MemberDatetimeOptionsetField('DateFormat', 'DateFormat');
-		$this->assertTrue($field->validate());
+		$this->assertTrue($field->validate(null));
 		$_POST['DateFormat_custom'] = 'dd MM yyyy';
-		$this->assertTrue($field->validate());
+		$this->assertTrue($field->validate(null));
 		$_POST['DateFormat_custom'] = 'sdfdsfdfd1244';
-		$this->assertFalse($field->validate());
+		$this->assertFalse($field->validate(null));
 	}
 
 }
@@ -97,4 +97,4 @@ class MemberDatetimeOptionsetFieldTest_Controller extends Controller {
 		return 'test';
 	}
 
-}
\ No newline at end of file
+}