diff --git a/Server/Components/Pages/ServerConfig.razor.cs b/Server/Components/Pages/ServerConfig.razor.cs
index 86078ca4..e60be7f6 100644
--- a/Server/Components/Pages/ServerConfig.razor.cs
+++ b/Server/Components/Pages/ServerConfig.razor.cs
@@ -7,6 +7,7 @@ using Remotely.Server.Models;
 using Remotely.Server.Services;
 using Remotely.Shared.Entities;
 using Remotely.Shared.Interfaces;
+using System.Net;
 using System.Text.Json;
 
 namespace Remotely.Server.Components.Pages;
@@ -105,12 +106,15 @@ public partial class ServerConfig : AuthComponentBase
 
     private void AddKnownProxy()
     {
-        if (string.IsNullOrWhiteSpace(_knownProxyToAdd))
+        if (IPAddress.TryParse(_knownProxyToAdd, out _))
         {
-            return;
+            Input.KnownProxies.Add(_knownProxyToAdd);
+        }
+        else
+        {
+            ToastService.ShowToast2("Invalid IP address.", Enums.ToastType.Warning);
         }
 
-        Input.KnownProxies.Add(_knownProxyToAdd);
         _knownProxyToAdd = string.Empty;
     }
 
diff --git a/Server/Program.cs b/Server/Program.cs
index b7549845..d6de58a2 100644
--- a/Server/Program.cs
+++ b/Server/Program.cs
@@ -181,7 +181,10 @@ services.Configure<ForwardedHeadersOptions>(options =>
     {
         foreach (var proxy in knownProxies)
         {
-            options.KnownProxies.Add(IPAddress.Parse(proxy));
+            if (IPAddress.TryParse(proxy, out var ip))
+            {
+                options.KnownProxies.Add(ip);
+            }
         }
     }
 });