diff --git a/HISTORY.md b/HISTORY.md
index c23c12f1..e0b686a0 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -12,6 +12,10 @@ http://visjs.org
 
 - Do not change `backgroundColor` when not provided in options. Thanks @ozydingo.
 
+### Timeline
+
+- Fixed #1001: First element of group style being cut.
+
 
 ## 2015-07-03, version 4.4.0
 
diff --git a/lib/timeline/component/Group.js b/lib/timeline/component/Group.js
index 51e32ee2..d10c3ba2 100644
--- a/lib/timeline/component/Group.js
+++ b/lib/timeline/component/Group.js
@@ -120,11 +120,11 @@ Group.prototype.setData = function(data) {
 
   // update style
   if (this.style) {
-    util.removeCssText(this.dom.label, 'vis-' + this.style);
+    util.removeCssText(this.dom.label, this.style);
     this.style = null;
   }
   if (data && data.style) {
-    util.addCssText(this.dom.label, 'vis-' + data.style);
+    util.addCssText(this.dom.label, data.style);
     this.style = data.style;
   }
 };