diff --git a/src/PSProxmoxVE.Core/Client/PveHttpClient.cs b/src/PSProxmoxVE.Core/Client/PveHttpClient.cs
index e9d4145..7edc624 100644
--- a/src/PSProxmoxVE.Core/Client/PveHttpClient.cs
+++ b/src/PSProxmoxVE.Core/Client/PveHttpClient.cs
@@ -353,6 +353,17 @@ namespace PSProxmoxVE.Core.Client
             {
                 response = await _httpClient.SendAsync(request).ConfigureAwait(false);
             }
+            catch (TaskCanceledException ex) when (ex.InnerException is TimeoutException)
+            {
+                // HttpClient.Timeout elapsed. In .NET 5+, HttpClient surfaces transport
+                // timeouts as TaskCanceledException with a TimeoutException inner —
+                // distinguishing them from caller-driven CancellationToken cancellation.
+                var seconds = _httpClient.Timeout == System.Threading.Timeout.InfiniteTimeSpan
+                    ? "infinite"
+                    : _httpClient.Timeout.TotalSeconds.ToString("0", System.Globalization.CultureInfo.InvariantCulture) + "s";
+                throw new PveApiException(HttpStatusCode.RequestTimeout,
+                    $"Request timed out after {seconds}.", resource, httpMethod, ex);
+            }
             catch (HttpRequestException ex)
             {
                 throw new PveApiException(HttpStatusCode.ServiceUnavailable,
diff --git a/tests/PSProxmoxVE.Core.Tests/Client/PveHttpClientTimeoutTests.cs b/tests/PSProxmoxVE.Core.Tests/Client/PveHttpClientTimeoutTests.cs
index ae0d9dc..68200a8 100644
--- a/tests/PSProxmoxVE.Core.Tests/Client/PveHttpClientTimeoutTests.cs
+++ b/tests/PSProxmoxVE.Core.Tests/Client/PveHttpClientTimeoutTests.cs
@@ -1,9 +1,12 @@
 using System;
+using System.Net;
 using System.Net.Http;
 using System.Reflection;
 using System.Threading;
+using System.Threading.Tasks;
 using PSProxmoxVE.Core.Authentication;
 using PSProxmoxVE.Core.Client;
+using PSProxmoxVE.Core.Exceptions;
 using Xunit;
 
 namespace PSProxmoxVE.Core.Tests.Client
@@ -17,6 +20,14 @@ namespace PSProxmoxVE.Core.Tests.Client
             return (HttpClient)field.GetValue(client)!;
         }
 
+        private static void SetInnerHttpClient(PveHttpClient client, HttpClient newInner)
+        {
+            var field = typeof(PveHttpClient).GetField("_httpClient",
+                BindingFlags.Instance | BindingFlags.NonPublic)!;
+            ((HttpClient)field.GetValue(client)!).Dispose();
+            field.SetValue(client, newInner);
+        }
+
         private static PveSession NewSession()
         {
             return new PveSession("pve.example.com", 8006, false,
@@ -56,13 +67,35 @@ namespace PSProxmoxVE.Core.Tests.Client
         }
 
         [Fact]
-        public void DefaultSessionTimeoutIs100Seconds()
+        public async Task SendAsync_TimeoutFires_ThrowsPveApiExceptionWithRequestTimeout()
         {
             var session = NewSession();
-
             using var client = new PveHttpClient(session);
 
-            Assert.Equal(TimeSpan.FromSeconds(100), GetInnerHttpClient(client).Timeout);
+            // Swap in an HttpClient with a delaying handler and a 50ms timeout so
+            // HttpClient.Timeout fires reliably without any real network.
+            var delayingClient = new HttpClient(new DelayingHandler(TimeSpan.FromSeconds(30)))
+            {
+                Timeout = TimeSpan.FromMilliseconds(50)
+            };
+            SetInnerHttpClient(client, delayingClient);
+
+            var ex = await Assert.ThrowsAsync<PveApiException>(() => client.GetAsync("version"));
+            Assert.Equal(HttpStatusCode.RequestTimeout, ex.StatusCode);
+            Assert.Contains("timed out", ex.Message, StringComparison.OrdinalIgnoreCase);
+        }
+
+        private sealed class DelayingHandler : HttpMessageHandler
+        {
+            private readonly TimeSpan _delay;
+            public DelayingHandler(TimeSpan delay) { _delay = delay; }
+
+            protected override async Task<HttpResponseMessage> SendAsync(
+                HttpRequestMessage request, CancellationToken cancellationToken)
+            {
+                await Task.Delay(_delay, cancellationToken).ConfigureAwait(false);
+                return new HttpResponseMessage(HttpStatusCode.OK);
+            }
         }
     }
 }