diff --git a/api-generator/components/timeline.js b/api-generator/components/timeline.js
index 3443c78a6..a7b30cee4 100644
--- a/api-generator/components/timeline.js
+++ b/api-generator/components/timeline.js
@@ -9,7 +9,7 @@ const TimelineProps = [
         name: "align",
         type: "string",
         default: "left",
-        description: 'Position of the timeline bar relative to the content. Valid values are "left", "right" for vertical layout and "top", "bottom" for horizontal layout.'
+        description: 'Position of the timeline bar relative to the content. Valid values are "left", "right" and "alternate" for vertical layout and "top", "bottom" for horizontal layout.'
     },
     {
         name: "layout",
diff --git a/src/components/timeline/Timeline.d.ts b/src/components/timeline/Timeline.d.ts
index 31ca89aea..c5fe3acab 100644
--- a/src/components/timeline/Timeline.d.ts
+++ b/src/components/timeline/Timeline.d.ts
@@ -1,7 +1,7 @@
 import { VNode } from 'vue';
 import { ClassComponent, GlobalComponentConstructor } from '../ts-helpers';
 
-type TimelineVerticalAlignType = 'left' | 'right' | undefined;
+type TimelineVerticalAlignType = 'left' | 'right' | 'alternate' | undefined;
 
 type TimelineHorizontalAlignType = 'top' | 'bottom' | undefined;