diff --git a/VpSharp.Commands/CommandsExtension.cs b/VpSharp.Commands/CommandsExtension.cs
index e59597d..1d799e9 100644
--- a/VpSharp.Commands/CommandsExtension.cs
+++ b/VpSharp.Commands/CommandsExtension.cs
@@ -22,7 +22,9 @@ public sealed class CommandsExtension : VirtualParadiseClientExtension
     /// </summary>
     /// <param name="client">The owning client.</param>
     /// <param name="configuration">The configuration to use.</param>
-    /// <exception cref="ArgumentNullException"><paramref name="configuration" /> is <see langword="null" />.</exception>
+    /// <exception cref="ArgumentNullException">
+    ///     <paramref name="client" /> or <paramref name="configuration" /> is <see langword="null" />.
+    /// </exception>
     public CommandsExtension(VirtualParadiseClient client, CommandsExtensionConfiguration configuration)
         : base(client)
     {
diff --git a/VpSharp/src/ClientExtensions/VirtualParadiseClientExtension.cs b/VpSharp/src/ClientExtensions/VirtualParadiseClientExtension.cs
index 20c4d76..8b0d6ab 100644
--- a/VpSharp/src/ClientExtensions/VirtualParadiseClientExtension.cs
+++ b/VpSharp/src/ClientExtensions/VirtualParadiseClientExtension.cs
@@ -11,9 +11,10 @@ public abstract class VirtualParadiseClientExtension
     ///     Initializes a new instance of the <see cref="VirtualParadiseClientExtension" /> class.
     /// </summary>
     /// <param name="client">The owning client.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="client" /> is <see langword="null" />.</exception>
     protected VirtualParadiseClientExtension(VirtualParadiseClient client)
     {
-        Client = client;
+        Client = client ?? throw new ArgumentNullException(nameof(client));
     }
 
     /// <summary>