diff --git src/wp-includes/plugin.php src/wp-includes/plugin.php
index df4ba8d..151f599 100644
--- src/wp-includes/plugin.php
+++ src/wp-includes/plugin.php
@@ -80,6 +80,13 @@ if ( ! isset( $wp_current_filter ) )
  * @return boolean true
  */
 function add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1 ) {
+	$tag_a = explode(' ', $tag);
+	if (isset($tag_a[1])) { //Check if the array is longer than 1 element
+		foreach ($tag_a as $t) {
+			add_filter($t, $function_to_add, $priority, $accepted_args);
+		}
+       return;
+	}
+	
 	global $wp_filter, $merged_filters;
 
 	$idx = _wp_filter_build_unique_id($tag, $function_to_add, $priority);