diff --git a/class-404-template.php b/class-404-template.php
index add91ef..ddfff55 100644
--- a/class-404-template.php
+++ b/class-404-template.php
@@ -44,8 +44,9 @@ public function download() {
 
 		$u = wp_upload_dir();
 
-		$basedir = str_replace( $this->uploads_basedir(), '', $u['basedir'] );
-		$abspath = $basedir . $this->get_local_path();
+		$remove = str_replace( get_option( 'siteurl' ), '', $u['baseurl'] );
+		$basedir = str_replace( $remove, '', $u['basedir'] );
+		$abspath = $basedir . $this->get_dated_path();
 		$dir = dirname( $abspath );
 
 		if ( !is_dir( $dir ) && !wp_mkdir_p( $dir ) ) {
@@ -55,7 +56,9 @@ public function download() {
 		$saved_image = $wp_filesystem->put_contents( $abspath, $this->response['body'], FS_CHMOD_FILE ); // predefined mode settings for WP files
 
 		if ( $saved_image ) {
-			wp_redirect( get_site_url( get_current_blog_id(), $this->get_local_path() ) );
+			$path = $this->get_ms_adjusted_path();
+			$redirect = get_site_url( get_current_blog_id(), $path );
+			wp_redirect( $redirect );
 			exit;
 		}else {
 			$this->display_and_exit( "Please check permissions. Could not write image $dir" );
@@ -84,6 +87,7 @@ public function display_and_exit( $message=false ) {
 	 */
 	public function allow_path() {
 		$path = $this->get_remote_path();
+
 		if ( empty( $path ) ) { return false; }
 
 		$allowed_paths = array(
@@ -120,12 +124,31 @@ public function get_siteurl() {
 			$url = str_replace( array( 'http://', 'https://' ), '', UBP_LIVE_DOMAIN );
 			$url = 'http://' . $url;
 
-		}else if ( defined( 'UBP_SITEURL' ) && false !== UBP_SITEURL ) {
-		
+		}else if ( is_multisite() && ( $siteurl = get_option( '_ubp_site_url' ) ) ) {
+
+			$url = parse_url( $siteurl );
+			$url = 'http://' . $url['host'] . @$url['path'];
+
+		}else if ( is_multisite() && defined( 'UBP_SITEURL' ) && false !== UBP_SITEURL ) {
+
+
+			$details = get_blog_details();
+			$url = parse_url( UBP_SITEURL );
+			$ms_url = '';
+			if ( SUBDOMAIN_INSTALL ) {
+				$parts = explode( '.', $details->domain );
+				$ms_url = $parts[0] . '.' . $url['host'];
+			} else {
+				$ms_url = $url['host'] . $details->path;
+			}
+			$url = 'http://' . $ms_url . @$url['path'];
+
+		} else if ( defined( 'UBP_SITEURL' ) && false !== UBP_SITEURL ) {
+
 			$url = parse_url( UBP_SITEURL );
 			$url = 'http://' . $url['host'] . @$url['path'];
 
-		}else if ( !is_multisite() ) {
+		} else {
 			// Nothing set... Get original siteurl from database
 
 			remove_filter( 'option_siteurl', '_config_wp_siteurl' );
@@ -147,6 +170,27 @@ public function get_domain() {
 		return $this->domain;
 	}
 
+	public function get_dated_path() {
+		$path = $this->get_local_path();
+
+		if ( function_exists( 'is_multisite' ) && is_multisite() && strpos( $path, '/files/' ) === 0 ) {
+			$path = str_replace( '/files', '', $path );
+		}
+
+		return $path;		
+	}
+
+	public function get_ms_adjusted_path() {
+		$path = $this->get_local_path();
+
+		//switch to the "new" multisite files location
+		if ( function_exists( 'is_multisite' ) && is_multisite() && strpos( $path, '/files/' ) === 0 ) {
+			$path = 'wp-content/uploads/sites/' . get_current_blog_id() . str_replace( '/files', '', $path );
+		}
+
+		return $path;
+	}
+
 	public function get_auth() {
 		if ( !isset( $this->auth ) ) {
 			$user = parse_url( $this->get_siteurl(), PHP_URL_USER );
@@ -170,8 +214,10 @@ public function get_local_path() {
 		// If local install is in a subdirectory, modify path to request from WordPress root
 		$local_wordpress_path = parse_url( get_site_url(), PHP_URL_PATH ) . '/';
 		$requested_path = parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH );
+
 		if (substr($requested_path, 0, strlen($local_wordpress_path)) == $local_wordpress_path) {
-		    $requested_path = substr($requested_path, strlen($local_wordpress_path)-1, strlen($requested_path));
+		    //$requested_path = substr($requested_path, strlen($local_wordpress_path), strlen($requested_path));
+			$requested_path = substr($requested_path, strlen($local_wordpress_path)-1, strlen($requested_path));
 		}
 
 		$this->local_path = $requested_path;
@@ -186,6 +232,7 @@ public function get_remote_path() {
 
 		// If remote install is in a subdirectory, prepend the remote path
 		$remote_path = parse_url( $this->get_siteurl(), PHP_URL_PATH );
+
 		if ( !empty( $remote_path ) ) {
 			$this->remote_path = $remote_path . $this->get_local_path();
 		}else {
diff --git a/class-get-public-ip.php b/class-get-public-ip.php
index 47f3f0d..e035817 100644
--- a/class-get-public-ip.php
+++ b/class-get-public-ip.php
@@ -44,7 +44,7 @@ function __toString() {
 	public function get_ip( $url, $args=array() ) {
 		$defaults = array( 
 			'method' => 'GET',
-			'referer'=> $domain,
+			'referer'=> $this->domain,
 			'body' => '',
 			'index' => 0,
 		);
@@ -58,7 +58,7 @@ public function get_ip( $url, $args=array() ) {
 		);
 
 		$response = wp_remote_get( $url, $query_args );
-		
+
 		if ( ! is_wp_error( $response ) ) {
 			$body = strip_tags($response['body']);
 
diff --git a/class-helpers.php b/class-helpers.php
index e546bd3..a95a7a9 100644
--- a/class-helpers.php
+++ b/class-helpers.php
@@ -13,7 +13,7 @@ static public function init_404_template( $template ) {
 	}
 
 	static public function requirements_check() {
-		add_action( 'admin_init', 'UBP_Helpers::require_no_multisite', 11 );
+		//add_action( 'admin_init', 'UBP_Helpers::require_no_multisite', 11 );
 		add_action( 'admin_notices', 'UBP_Helpers::request_uploads_writable' );
 		add_action( 'admin_footer', 'UBP_Helpers::request_permalinks_enabled' );
 	}
@@ -21,7 +21,7 @@ static public function requirements_check() {
 	/**
 	 * Require single-site install before activating.
 	 */
-	static public function require_no_multisite() {
+	static public function require_no_multisite() {		
 		if ( function_exists( 'is_multisite' ) && !is_multisite() ) { return true; }
 
 		if ( is_admin() && (!defined('DOING_AJAX') || !DOING_AJAX) ) {
@@ -64,4 +64,31 @@ static public function request_uploads_writable() {
 		return false;
 	}
 
+	static public function print_multisite_setting( $id ) {
+		switch_to_blog( $id );
+		$ubp_site_url = get_option( '_ubp_site_url' );
+		restore_current_blog();
+		?>
+		<tr class="form-field">
+			<th scope="row">UBP Site URL</th>
+			<td><input class="all-options" name="option[_ubp_site_url]" type="text" id="ubp_site_url" value="<?php echo $ubp_site_url ?>" size="40"></td>
+		</tr>
+		<?php
+	}
+
+	static public function ubp_extra_paths( $allowed_paths ) {
+		$details = get_blog_details();
+		$allowed_paths[] = $details->path . 'files/';
+		$allowed_paths[] = $details->path . 'wp-content/uploads/';
+		return $allowed_paths;
+	}
+
+	static function stop_ms_files_rewriting() {
+        $path = ABSPATH . 'wp-content/uploads/sites/' . get_current_blog_id();
+        define( 'BLOGUPLOADDIR', $path );
+	}
+
+	static function pre_site_option_ms_files_rewriting( $option ) {
+		return 0; //return 0, not FALSE
+	}
 }
\ No newline at end of file
diff --git a/readme.txt b/readme.txt
index f330612..c9e9b0c 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,5 +1,5 @@
 === Uploads by Proxy ===
-Contributors: pdclark
+Contributors: pdclark, jrfoell
 Author URI: http://pdclark.com
 Tags: localhost, local, development, staging, uploads, media library, xampp, mamp, wamp, git, svn, subversion
 Requires at least: 3.1
@@ -22,6 +22,28 @@ In most cases, you should be able to activate the plugin and go. If the plugin d
 
 If you are on a staging server (not a local development environment) you may need to force the plugin to run with `define( 'UBP_IS_LOCAL', true );` in `wp-config.php`. Do not set this on a live site!
 
+= Multi-Site =
+
+Multi-site support is available in WordPress 3.6+ but it requires additional configuration. 
+
+In wp-config.php, in addition to the 'UBP_SITEURL' define, also add this:
+
+	define('UPLOADBLOGSDIR', 'wp-content/uploads/sites');
+
+In your .htaccess, comment out the "ms-files" line if present. It will look something like one of these two lines:
+
+	#RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [L]
+	#RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]
+
+Also in your .htaccess, replace the following 'Normal' rewrite rules with the UBP Multisite rule below:
+
+# Normal
+#RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
+# UBP Multisite
+RewriteRule ^[_0-9a-zA-Z-]+/(wp-(content|admin|includes).*) $1 [L]
+
+This last .htaccess change is needed due to a bug that either manifests itself in Apache or in the default distributed WordPress Multi-Site .htaccess (https://core.trac.wordpress.org/ticket/20746)
+
 
 == Installation ==
 
@@ -82,6 +104,10 @@ function ubp_ip_url( $url, $domain ) {
 
 == Changelog ==
 
+= 1.1.3 =
+
+Multi-Site support (requires extra manual configuration)
+
 = 1.1.2 =
 
 * Fix: Resolve a warning output in debug environments. (Static function not declared as static.)
diff --git a/uploads-by-proxy.php b/uploads-by-proxy.php
index a648e4c..2f77103 100644
--- a/uploads-by-proxy.php
+++ b/uploads-by-proxy.php
@@ -5,7 +5,7 @@
 Author: Paul Clark
 Author URI: http://pdclark.com
 Description: Load images from production site if missing in development environment. Activate by using either <code>define('WP_SITEURL', 'http://development-domain.com');</code> or <code>define('UBP_SITEURL', 'http://live-domain.com/wordpress');</code> in wp-config.php.
-Version: 1.1.2
+Version: 1.1.3ms
 */
 
 /**
@@ -54,3 +54,10 @@
 	add_action( 'admin_init', 'UBP_Helpers::requirements_check' );
 	add_filter( '404_template', 'UBP_Helpers::init_404_template' );
 }
+
+if ( function_exists( 'is_multisite' ) && is_multisite() ) {
+	add_action( 'wpmueditblogaction', 'UBP_Helpers::print_multisite_setting' );
+	add_filter( 'ubp_allowed_paths', 'UBP_Helpers::ubp_extra_paths' );
+	add_action( 'init','UBP_Helpers::stop_ms_files_rewriting' );
+	add_filter( 'pre_site_option_ms_files_rewriting', 'UBP_Helpers::pre_site_option_ms_files_rewriting' );
+}