diff --git a/www/manager6/qemu/PCIEdit.js b/www/manager6/qemu/PCIEdit.js
index 4e8ed74..3df6437 100644
--- a/www/manager6/qemu/PCIEdit.js
+++ b/www/manager6/qemu/PCIEdit.js
@@ -83,10 +83,10 @@ Ext.define('PVE.qemu.PCIInputPanel', {
                     return;
                 }
                 // try to find out if there are more devices in that iommu group
-                let id = path.substring(0, 5); // 00:00
+                let id = path.substring(0, path.indexOf('.')); // 0000:00:00
                 let count = 0;
                 pcisel.getStore().each(({ data }) => {
-                    if (data.iommugroup === iommu && data.id.substring(0, 5) !== id) {
+                    if (data.iommugroup === iommu && !data.id.startsWith(id)) {
                         count++;
                         return false;
                     }