diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 578ce0255a..755fbb7957 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -122,11 +122,4 @@
 		<exclude name="PHPCompatibility.PHP.NewInterfaces.jsonserializableFound"/>
 	</rule>
 
-	<!-- Whitelist the WP Core mysql_to_rfc3339() function. -->
-	<rule ref="PHPCompatibility.PHP.RemovedExtensions">
-		<properties>
-			<property name="functionWhitelist" type="array" value="mysql_to_rfc3339"/>
-		</properties>
-	</rule>
-
 </ruleset>