diff --git a/dotnet/src/webdriver/DevTools/DevToolsDomains.cs b/dotnet/src/webdriver/DevTools/DevToolsDomains.cs
index 4b8e688e1029b..bf2246bb0bffa 100644
--- a/dotnet/src/webdriver/DevTools/DevToolsDomains.cs
+++ b/dotnet/src/webdriver/DevTools/DevToolsDomains.cs
@@ -82,7 +82,7 @@ public abstract class DevToolsDomains
         /// Initializes the supplied DevTools session's domains for the specified browser version.
         /// </summary>
         /// <param name="protocolVersion">The version of the DevTools Protocol to use.</param>
-        /// <param name="session">The <see cref="DevToolsSession"/> for which to initialiize the domains.</param>
+        /// <param name="session">The <see cref="DevToolsSession"/> for which to initialize the domains.</param>
         /// <returns>The <see cref="DevToolsDomains"/> object containing the version-specific domains.</returns>
         /// <exception cref="ArgumentException">If <paramref name="protocolVersion"/> is negative.</exception>
         /// <exception cref="WebDriverException">If the desired protocol version is not supported.</exception>
@@ -95,7 +95,7 @@ public static DevToolsDomains InitializeDomains(int protocolVersion, DevToolsSes
         /// Initializes the supplied DevTools session's domains for the specified browser version within the specified number of versions.
         /// </summary>
         /// <param name="protocolVersion">The version of the DevTools Protocol to use.</param>
-        /// <param name="session">The <see cref="DevToolsSession"/> for which to initialiize the domains.</param>
+        /// <param name="session">The <see cref="DevToolsSession"/> for which to initialize the domains.</param>
         /// <param name="versionRange">The range of versions within which to match the provided version number. Defaults to 5 versions.</param>
         /// <returns>The <see cref="DevToolsDomains"/> object containing the version-specific domains.</returns>
         /// <exception cref="ArgumentException">If <paramref name="protocolVersion"/> is negative.</exception>
diff --git a/dotnet/src/webdriver/DevTools/v130/V130Domains.cs b/dotnet/src/webdriver/DevTools/v130/V130Domains.cs
index d75c8ac61de59..75e7bac035802 100644
--- a/dotnet/src/webdriver/DevTools/v130/V130Domains.cs
+++ b/dotnet/src/webdriver/DevTools/v130/V130Domains.cs
@@ -17,6 +17,10 @@
 // under the License.
 // </copyright>
 
+using System;
+
+#nullable enable
+
 namespace OpenQA.Selenium.DevTools.V130
 {
     /// <summary>
@@ -24,15 +28,16 @@ namespace OpenQA.Selenium.DevTools.V130
     /// </summary>
     public class V130Domains : DevToolsDomains
     {
-        private DevToolsSessionDomains domains;
+        private readonly DevToolsSessionDomains domains;
 
         /// <summary>
         /// Initializes a new instance of the V130Domains class.
         /// </summary>
         /// <param name="session">The DevToolsSession to use with this set of domains.</param>
+        /// <exception cref="ArgumentNullException">If <paramref name="session"/> is <see langword="null"/>.</exception>
         public V130Domains(DevToolsSession session)
         {
-            this.domains = new DevToolsSessionDomains(session);
+            this.domains = new DevToolsSessionDomains(session ?? throw new ArgumentNullException(nameof(session)));
         }
 
         /// <summary>
diff --git a/dotnet/src/webdriver/DevTools/v131/V131Domains.cs b/dotnet/src/webdriver/DevTools/v131/V131Domains.cs
index 66fd521bf9f09..d7be2850d038e 100644
--- a/dotnet/src/webdriver/DevTools/v131/V131Domains.cs
+++ b/dotnet/src/webdriver/DevTools/v131/V131Domains.cs
@@ -17,6 +17,10 @@
 // under the License.
 // </copyright>
 
+using System;
+
+#nullable enable
+
 namespace OpenQA.Selenium.DevTools.V131
 {
     /// <summary>
@@ -24,15 +28,16 @@ namespace OpenQA.Selenium.DevTools.V131
     /// </summary>
     public class V131Domains : DevToolsDomains
     {
-        private DevToolsSessionDomains domains;
+        private readonly DevToolsSessionDomains domains;
 
         /// <summary>
         /// Initializes a new instance of the V131Domains class.
         /// </summary>
         /// <param name="session">The DevToolsSession to use with this set of domains.</param>
+        /// <exception cref="ArgumentNullException">If <paramref name="session"/> is <see langword="null"/>.</exception>
         public V131Domains(DevToolsSession session)
         {
-            this.domains = new DevToolsSessionDomains(session);
+            this.domains = new DevToolsSessionDomains(session ?? throw new ArgumentNullException(nameof(session)));
         }
 
         /// <summary>
diff --git a/dotnet/src/webdriver/DevTools/v132/V132Domains.cs b/dotnet/src/webdriver/DevTools/v132/V132Domains.cs
index e213729809e8d..095893698d090 100644
--- a/dotnet/src/webdriver/DevTools/v132/V132Domains.cs
+++ b/dotnet/src/webdriver/DevTools/v132/V132Domains.cs
@@ -17,6 +17,10 @@
 // under the License.
 // </copyright>
 
+using System;
+
+#nullable enable
+
 namespace OpenQA.Selenium.DevTools.V132
 {
     /// <summary>
@@ -24,15 +28,16 @@ namespace OpenQA.Selenium.DevTools.V132
     /// </summary>
     public class V132Domains : DevToolsDomains
     {
-        private DevToolsSessionDomains domains;
+        private readonly DevToolsSessionDomains domains;
 
         /// <summary>
         /// Initializes a new instance of the V132Domains class.
         /// </summary>
         /// <param name="session">The DevToolsSession to use with this set of domains.</param>
+        /// <exception cref="ArgumentNullException">If <paramref name="session"/> is <see langword="null"/>.</exception>
         public V132Domains(DevToolsSession session)
         {
-            this.domains = new DevToolsSessionDomains(session);
+            this.domains = new DevToolsSessionDomains(session ?? throw new ArgumentNullException(nameof(session)));
         }
 
         /// <summary>
diff --git a/dotnet/src/webdriver/DevTools/v85/V85Domains.cs b/dotnet/src/webdriver/DevTools/v85/V85Domains.cs
index 885296bbeb556..4285f0262de52 100644
--- a/dotnet/src/webdriver/DevTools/v85/V85Domains.cs
+++ b/dotnet/src/webdriver/DevTools/v85/V85Domains.cs
@@ -17,6 +17,10 @@
 // under the License.
 // </copyright>
 
+using System;
+
+#nullable enable
+
 namespace OpenQA.Selenium.DevTools.V85
 {
     /// <summary>
@@ -24,15 +28,16 @@ namespace OpenQA.Selenium.DevTools.V85
     /// </summary>
     public class V85Domains : DevToolsDomains
     {
-        private DevToolsSessionDomains domains;
+        private readonly DevToolsSessionDomains domains;
 
         /// <summary>
         /// Initializes a new instance of the V85Domains class.
         /// </summary>
         /// <param name="session">The DevToolsSession to use with this set of domains.</param>
+        /// <exception cref="ArgumentNullException">If <paramref name="session"/> is <see langword="null"/>.</exception>
         public V85Domains(DevToolsSession session)
         {
-            this.domains = new DevToolsSessionDomains(session);
+            this.domains = new DevToolsSessionDomains(session ?? throw new ArgumentNullException(nameof(session)));
         }
 
         /// <summary>