diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 209636dd75..e7a4e1ddfb 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -581,11 +581,18 @@ function addslashes_gpc($gpc) {
 }
 
 
-function stripslashes_deep($value)
-{
+function stripslashes_deep($value) {
 	 $value = is_array($value) ?
-							 array_map('stripslashes_deep', $value) :
-							 stripslashes($value);
+		 array_map('stripslashes_deep', $value) :
+		 stripslashes($value);
+
+	 return $value;
+}
+
+function urlencode_deep($value) {
+	 $value = is_array($value) ?
+		 array_map('urlencode_deep', $value) :
+		 urlencode($value);
 
 	 return $value;
 }
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index d7b2a1ae8d..c9d46a67f1 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -808,6 +808,7 @@ function add_query_arg() {
 	parse_str($query, $qs);
 	if ( get_magic_quotes_gpc() )
 		$qs = stripslashes_deep($qs); // parse_str() adds slashes if magicquotes is on.  See: http://php.net/parse_str
+	$qs = urlencode_deep($qs);
 	if ( is_array(func_get_arg(0)) ) {
 		$kayvees = func_get_arg(0);
 		$qs = array_merge($qs, $kayvees);