diff --git a/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.html b/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.html
index 1d622663a7..434a6f9d45 100644
--- a/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.html
+++ b/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.html
@@ -9,7 +9,7 @@
     </vdr-ab-right>
 </vdr-action-bar>
 <div class="group-wrapper">
-    <table class="table group-list" *ngIf="!(listIsEmpty$ | async); else emptyPlaceholder">
+    <table class="table group-list" [class.expanded]="activeGroup$ | async" *ngIf="!(listIsEmpty$ | async); else emptyPlaceholder">
         <tbody>
             <tr *ngFor="let group of groups$ | async" [class.active]="group.id === (activeGroup$ | async)?.id">
                 <td class="left align-middle"><vdr-entity-info [entity]="group"></vdr-entity-info></td>
diff --git a/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.scss b/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.scss
index 791e7aae1f..cf3566cdbf 100644
--- a/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.scss
+++ b/packages/admin-ui/src/lib/customer/src/components/customer-group-list/customer-group-list.component.scss
@@ -12,6 +12,10 @@
         tr.active {
             background-color: $color-grey-200;
         }
+        &.expanded {
+            // Fix for Firefox layout https://github.com/vendure-ecommerce/vendure/issues/531
+            width: calc(100% - 40vw);
+        }
     }
 }
 .group-members {