diff --git a/src/System.Private.CoreLib/src/Internal/Console.cs b/src/System.Private.CoreLib/src/Internal/Console.cs
index ecb751f8b378..e2d728c647f6 100644
--- a/src/System.Private.CoreLib/src/Internal/Console.cs
+++ b/src/System.Private.CoreLib/src/Internal/Console.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Text;
 using Microsoft.Win32.SafeHandles;
@@ -27,7 +28,7 @@ public static unsafe void Write(string s)
             }
         }
 
-        public static void WriteLine(string s) =>
+        public static void WriteLine(string? s) =>
             Write(s + Environment.NewLine);
 
         public static void WriteLine() =>
diff --git a/src/System.Private.CoreLib/src/System/ValueType.cs b/src/System.Private.CoreLib/src/System/ValueType.cs
index 516014f34ec4..c3c2b1f45ccd 100644
--- a/src/System.Private.CoreLib/src/System/ValueType.cs
+++ b/src/System.Private.CoreLib/src/System/ValueType.cs
@@ -11,6 +11,7 @@
 **
 ===========================================================*/
 
+#nullable enable
 using System;
 using System.Reflection;
 using System.Runtime.CompilerServices;
@@ -22,7 +23,7 @@ namespace System
     [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")] 
     public abstract class ValueType
     {
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             if (null == obj)
             {