diff --git a/wp-includes/class-wp-xmlrpc-server.php b/wp-includes/class-wp-xmlrpc-server.php
index 48422c6a92..8661a44b4c 100644
--- a/wp-includes/class-wp-xmlrpc-server.php
+++ b/wp-includes/class-wp-xmlrpc-server.php
@@ -5721,6 +5721,11 @@ class wp_xmlrpc_server extends IXR_Server {
 			return $this->error;
 		}
 
+		if ( is_multisite() && upload_is_user_over_quota( false ) ) {
+			$this->error = new IXR_Error( 401, __( 'Sorry, you have used your space allocation.' ) );
+			return $this->error;
+		}
+
 		/**
 		 * Filter whether to preempt the XML-RPC media upload.
 		 *
diff --git a/wp-includes/ms-functions.php b/wp-includes/ms-functions.php
index e866e6e255..1fc709541c 100644
--- a/wp-includes/ms-functions.php
+++ b/wp-includes/ms-functions.php
@@ -2372,7 +2372,11 @@ function get_space_allowed() {
  * @return int of upload space available in bytes
  */
 function get_upload_space_available() {
-	$space_allowed = get_space_allowed() * 1024 * 1024;
+	$allowed = get_space_allowed();
+	if ( $allowed < 0 ) {
+		$allowed = 0;
+	}
+	$space_allowed = $allowed * 1024 * 1024;
 	if ( get_site_option( 'upload_space_check_disabled' ) )
 		return $space_allowed;
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 29f053e728..00cd9ee197 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34602';
+$wp_version = '4.4-alpha-34603';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.