diff --git a/types/animejs/index.d.ts b/types/animejs/index.d.ts
index 069187b15e..ad2d73fb2b 100644
--- a/types/animejs/index.d.ts
+++ b/types/animejs/index.d.ts
@@ -110,7 +110,7 @@ declare namespace anime {
 	}
 
 	interface AnimeTimelineInstance extends AnimeInstance {
-		add(params: AnimeAnimParams): AnimeTimelineInstance;
+		add(params: AnimeAnimParams, timelineOffset?: string | number): AnimeTimelineInstance;
 	}
 
 	// Helpers