diff --git a/src/wp-includes/class-json.php b/src/wp-includes/class-json.php
index 036150f1d8c3..147cdcb8cd1e 100644
--- a/src/wp-includes/class-json.php
+++ b/src/wp-includes/class-json.php
@@ -1,5 +1,5 @@
 <?php
-_deprecated_file( basename( __FILE__ ), '5.3.0', null, 'The PHP native JSON extension is now a requirement.' );
+_deprecated_file( basename( __FILE__ ), '5.3.0', '', 'The PHP native JSON extension is now a requirement.' );
 
 if ( ! class_exists( 'Services_JSON' ) ) :
 /* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
diff --git a/src/wp-includes/registration-functions.php b/src/wp-includes/registration-functions.php
index 347856e5434c..8dda8f844a6c 100644
--- a/src/wp-includes/registration-functions.php
+++ b/src/wp-includes/registration-functions.php
@@ -6,4 +6,4 @@
  * @deprecated 2.1.0
  */
 
-_deprecated_file( basename( __FILE__ ), '2.1.0', null, __( 'This file no longer needs to be included.' ) );
+_deprecated_file( basename( __FILE__ ), '2.1.0', '', __( 'This file no longer needs to be included.' ) );
diff --git a/src/wp-includes/registration.php b/src/wp-includes/registration.php
index a676e730b188..1e35b09bdc56 100644
--- a/src/wp-includes/registration.php
+++ b/src/wp-includes/registration.php
@@ -6,4 +6,4 @@
  * @deprecated 3.1.0
  */
 
-_deprecated_file( basename( __FILE__ ), '3.1.0', null, __( 'This file no longer needs to be included.' ) );
+_deprecated_file( basename( __FILE__ ), '3.1.0', '', __( 'This file no longer needs to be included.' ) );
diff --git a/src/wp-includes/spl-autoload-compat.php b/src/wp-includes/spl-autoload-compat.php
index 982d9c2a8345..29399d42b9bd 100644
--- a/src/wp-includes/spl-autoload-compat.php
+++ b/src/wp-includes/spl-autoload-compat.php
@@ -11,4 +11,4 @@
  * @access private
  */
 
-_deprecated_file( basename( __FILE__ ), '5.3.0', null, 'SPL can no longer be disabled as of PHP 5.3.' );
+_deprecated_file( basename( __FILE__ ), '5.3.0', '', 'SPL can no longer be disabled as of PHP 5.3.' );