diff --git a/server/src/lib/paloalto.js b/server/src/lib/paloalto.js
index 04028eb..4e1b524 100644
--- a/server/src/lib/paloalto.js
+++ b/server/src/lib/paloalto.js
@@ -69,7 +69,9 @@ async function updateUserIdMappings() {
 
     const net = ip.cidrSubnet(pAHost.cidr)
 
-    const devices = allDevices.filter(device => net.contains(device.ip))
+    const devices = allDevices.filter(
+      ({ ip }) => isIPv4(ip) && net.contains(ip)
+    )
 
     try {
       // console.log(pAHost.id, pAHost.description, devices.length)