diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 361bafde2..8ed3caa2b 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -860,7 +860,7 @@ declare module 'xterm' {
   /**
    * An object representing a range within the viewport of the terminal.
    */
-  interface IViewportRange {
+  export interface IViewportRange {
     /**
      * The start cell of the range.
      */