diff --git a/phpunit/tests/fonts/font-library/wpRestFontLibraryController/base.php b/phpunit/tests/fonts/font-library/wpRestFontLibraryController/base.php
index f1e712bab85b40..d794791abba497 100644
--- a/phpunit/tests/fonts/font-library/wpRestFontLibraryController/base.php
+++ b/phpunit/tests/fonts/font-library/wpRestFontLibraryController/base.php
@@ -29,6 +29,6 @@ public function tear_down() {
 		$reflection = new ReflectionClass( 'WP_Font_Library' );
 		$property   = $reflection->getProperty( 'collections' );
 		$property->setAccessible( true );
-		$property->setValue( array() );
+		$property->setValue( null, array() );
 	}
 }