diff --git a/src/libraries/Common/src/Interop/Windows/SChannel/Interop.SECURITY_STATUS.cs b/src/libraries/Common/src/Interop/Windows/SChannel/Interop.SECURITY_STATUS.cs
index 67370f9587fa08..dcf22b7c65b8f4 100644
--- a/src/libraries/Common/src/Interop/Windows/SChannel/Interop.SECURITY_STATUS.cs
+++ b/src/libraries/Common/src/Interop/Windows/SChannel/Interop.SECURITY_STATUS.cs
@@ -50,6 +50,7 @@ internal enum SECURITY_STATUS
         UnsupportedPreauth = unchecked((int)0x80090343),
         BadBinding = unchecked((int)0x80090346),
         DowngradeDetected = unchecked((int)0x80090350),
+        MutualAuthFailed = unchecked((int)0x8009035D),
         ApplicationProtocolMismatch = unchecked((int)0x80090367),
         NoRenegotiation = unchecked((int)0x00090360),
         KeySetDoesNotExist = unchecked((int)0x80090016)
diff --git a/src/libraries/System.Net.Security/src/System/Net/SecurityStatusAdapterPal.Windows.cs b/src/libraries/System.Net.Security/src/System/Net/SecurityStatusAdapterPal.Windows.cs
index a6b4e4115d48f4..7a1d48f35f1e63 100644
--- a/src/libraries/System.Net.Security/src/System/Net/SecurityStatusAdapterPal.Windows.cs
+++ b/src/libraries/System.Net.Security/src/System/Net/SecurityStatusAdapterPal.Windows.cs
@@ -9,7 +9,7 @@ namespace System.Net
 {
     internal static class SecurityStatusAdapterPal
     {
-        private const int StatusDictionarySize = 45;
+        private const int StatusDictionarySize = 46;
 
 #if DEBUG
         static SecurityStatusAdapterPal()
@@ -44,6 +44,7 @@ static SecurityStatusAdapterPal()
             { Interop.SECURITY_STATUS.InvalidToken, SecurityStatusPalErrorCode.InvalidToken },
             { Interop.SECURITY_STATUS.LogonDenied, SecurityStatusPalErrorCode.LogonDenied },
             { Interop.SECURITY_STATUS.MessageAltered, SecurityStatusPalErrorCode.MessageAltered },
+            { Interop.SECURITY_STATUS.MutualAuthFailed, SecurityStatusPalErrorCode.MutualAuthFailed },
             { Interop.SECURITY_STATUS.NoAuthenticatingAuthority, SecurityStatusPalErrorCode.NoAuthenticatingAuthority },
             { Interop.SECURITY_STATUS.NoImpersonation, SecurityStatusPalErrorCode.NoImpersonation },
             { Interop.SECURITY_STATUS.NoCredentials, SecurityStatusPalErrorCode.NoCredentials },
diff --git a/src/libraries/System.Net.Security/src/System/Net/SecurityStatusPal.cs b/src/libraries/System.Net.Security/src/System/Net/SecurityStatusPal.cs
index f4d79d578c8f2c..7a28d1448a7ec0 100644
--- a/src/libraries/System.Net.Security/src/System/Net/SecurityStatusPal.cs
+++ b/src/libraries/System.Net.Security/src/System/Net/SecurityStatusPal.cs
@@ -73,6 +73,7 @@ internal enum SecurityStatusPalErrorCode
         ApplicationProtocolMismatch,
         NoRenegotiation,
         KeySetDoesNotExist,
-        ContextExpiredError
+        ContextExpiredError,
+        MutualAuthFailed
     }
 }