diff --git a/js/types.ts b/js/types.ts
index e4a69f85..cbe039d9 100644
--- a/js/types.ts
+++ b/js/types.ts
@@ -391,6 +391,14 @@ export interface WebampWindow {
   hotkey?: string;
 }
 
+export interface WindowInfo {
+  key: WindowId;
+  height: number;
+  width: number;
+  x: number;
+  y: number;
+}
+
 export interface WindowState {
   focused: string;
   genWindows: { [name: string]: WebampWindow };