diff --git a/docs/timeline/index.html b/docs/timeline/index.html
index b777065786..95040ce181 100644
--- a/docs/timeline/index.html
+++ b/docs/timeline/index.html
@@ -703,13 +703,14 @@ <h2 id="Configuration_Options">Configuration Options</h2>
 
     <tr>
       <td>groupHeightMode</td>
-      <td>String</td>
+      <td>String or Number</td>
       <td>'auto'</td>
       <td>
         Specifies how the height of a group is calculated. Choose from 'auto','fixed', and 'fitItems'. <br />
         If it is set to 'auto' the height will be calculated based on a group label and visible items.<br />
         If it is set to 'fitItems' the height will be calculated based on the visible items only.<br />
-        While if it is set to 'fixed' the group will keep the same height even if there are no visible items in the window.
+        While if it is set to 'fixed' the group will keep the same height even if there are no visible items in the window.<br />
+        If it is set to a number, this will be the height of the row in number of pixels.
       </td>
     </tr>
 
diff --git a/lib/timeline/component/Group.js b/lib/timeline/component/Group.js
index b658430768..dd12c813cf 100644
--- a/lib/timeline/component/Group.js
+++ b/lib/timeline/component/Group.js
@@ -620,7 +620,9 @@ class Group {
 
     let items;
 
-    if (this.heightMode === 'fixed') {
+    if (typeof this.heightMode === 'number') {
+      return this.heightMode;
+    } else if (this.heightMode === 'fixed') {
       items = util.toArray(this.items);
     } else {
       // default or 'auto'
diff --git a/lib/timeline/optionsTimeline.js b/lib/timeline/optionsTimeline.js
index ba59913b7c..4db21e6579 100644
--- a/lib/timeline/optionsTimeline.js
+++ b/lib/timeline/optionsTimeline.js
@@ -80,7 +80,7 @@ let allOptions = {
     __type__: {object}
   },
   moment: {'function': 'function'},
-  groupHeightMode: {string},
+  groupHeightMode: {string, number},
   groupOrder: {string, 'function': 'function'},
   groupEditable: {
     add: { 'boolean': bool, 'undefined': 'undefined'},
@@ -238,7 +238,7 @@ let configureOptions = {
         year:       ''
       }
     },
-    groupHeightMode: ['auto', 'fixed', 'fitItems'],
+    groupHeightMode: ['auto', 'fixed', 'fitItems', 20],
     //groupOrder: {string, 'function': 'function'},
     groupsDraggable: false,
     height: '',
diff --git a/types/index.d.ts b/types/index.d.ts
index 77448d8387..6d9642484c 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -236,7 +236,7 @@ export type TimelineOptionsSnapFunction = (date: Date, scale: string, step: numb
 export type TimelineOptionsSnapType = null | TimelineOptionsSnapFunction;
 export type TimelineOptionsTemplateFunction = (item?: any, element?: any, data?: any) => string | HTMLElement;
 export type TimelineOptionsComparisonFunction = (a: any, b: any) => number;
-export type TimelineOptionsGroupHeightModeType = 'auto' | 'fixed' | 'fitItems';
+export type TimelineOptionsGroupHeightModeType = 'auto' | 'fixed' | 'fitItems' | number;
 export type TimelineOptionsClusterCriteriaFunction = (firstItem: TimelineItem, secondItem: TimelineItem) => boolean;
 export type TimelineOptionsCluster = {
   titleTemplate?: string;