diff --git a/src/primaite/simulator/network/physical_layer.py b/src/primaite/simulator/network/physical_layer.py
index b709fd0a..dfe54ded 100644
--- a/src/primaite/simulator/network/physical_layer.py
+++ b/src/primaite/simulator/network/physical_layer.py
@@ -58,11 +58,11 @@ class NIC(SimComponent):
     :param dns_servers: List of IP addresses of DNS servers used for name resolution.
     """
 
-    ip_address: Union[IPv4Address]
+    ip_address: IPv4Address
     "The IP address assigned to the NIC for communication on an IP-based network."
     subnet_mask: str
     "The subnet mask assigned to the NIC."
-    gateway: Union[IPv4Address]
+    gateway: IPV4Address
     "The default gateway IP address for forwarding network traffic to other networks. Randomly generated upon creation."
     mac_address: str = generate_mac_address()
     "The MAC address of the NIC. Defaults to a randomly set MAC address."