diff --git a/wp-admin/admin-ajax.php b/wp-admin/admin-ajax.php
index 5560b38834..00f590ad4b 100644
--- a/wp-admin/admin-ajax.php
+++ b/wp-admin/admin-ajax.php
@@ -860,7 +860,7 @@ case 'add-meta' :
 			'supplemental' => array('postid' => $pid)
 		) );
 	} else { // Update?
-		$mid = (int) array_pop( array_keys($_POST['meta']) );
+		$mid = (int) array_pop( $var_by_ref = array_keys($_POST['meta']) );
 		$key = stripslashes( $_POST['meta'][$mid]['key'] );
 		$value = stripslashes( $_POST['meta'][$mid]['value'] );
 		if ( '' == trim($key) )
diff --git a/wp-admin/includes/nav-menu.php b/wp-admin/includes/nav-menu.php
index ea8f8425ff..c93a886bed 100644
--- a/wp-admin/includes/nav-menu.php
+++ b/wp-admin/includes/nav-menu.php
@@ -337,7 +337,7 @@ function _wp_ajax_menu_quick_search( $request = array() ) {
 			while ( have_posts() ) {
 				the_post();
 				if ( 'markup' == $response_format ) {
-					echo walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', array( get_post( get_the_ID() ) ) ), 0, (object) $args );
+					echo walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', array( get_post( $var_by_ref = get_the_ID() ) ) ), 0, (object) $args );
 				} elseif ( 'json' == $response_format ) {
 					echo json_encode(
 						array(
diff --git a/wp-app.php b/wp-app.php
index ec35b4120c..68e96d4369 100644
--- a/wp-app.php
+++ b/wp-app.php
@@ -223,7 +223,7 @@ class AtomServer {
 	 */
 	function __construct() {
 
-		$this->script_name = array_pop( explode( '/', $_SERVER['SCRIPT_NAME'] ) );
+		$this->script_name = array_pop( $var_by_ref = explode( '/', $_SERVER['SCRIPT_NAME'] ) );
 		$this->app_base = site_url( $this->script_name . '/' );
 
 		$this->selectors = array(
diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index d56688edf1..ebf6a64139 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1369,7 +1369,7 @@ class wpdb {
 			// Return an array of row objects with keys from column 1
 			// (Duplicates are discarded)
 			foreach ( $this->last_result as $row ) {
-				$key = array_shift( get_object_vars( $row ) );
+				$key = array_shift( $var_by_ref = get_object_vars( $row ) );
 				if ( ! isset( $new_array[ $key ] ) )
 					$new_array[ $key ] = $row;
 			}