diff --git a/addon/utils/css-calculation.js b/addon/utils/css-calculation.js
index 98eb1ee5..a4ab2aa1 100644
--- a/addon/utils/css-calculation.js
+++ b/addon/utils/css-calculation.js
@@ -8,7 +8,8 @@
 */
 export function getBorderSpacing(el) {
   let css = getComputedStyle(el).borderSpacing; // '0px 0px'
-  let [horizontal, vertical] = css.split(' ');
+  let [horizontal, initialVertical] = css.split(' ');
+  let vertical = initialVertical === undefined ? horizontal : initialVertical;
 
   return {
     horizontal: parseFloat(horizontal),
diff --git a/package.json b/package.json
index 7bd05a52..5c9ec46d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@gynzy/ember-sortable",
-  "version": "4.0.9",
+  "version": "4.0.10",
   "description": "Sortable UI primitives for Ember.",
   "keywords": [
     "ember-addon",