From 481e782cc2ab53285a51b61f124e39de5c5bdcc8 Mon Sep 17 00:00:00 2001
From: EgorBo <egorbo@gmail.com>
Date: Tue, 31 May 2022 16:29:45 +0200
Subject: [PATCH] Use correct type for backward compatibility during binary
 serialization

---
 .../src/System/Collections/Generic/Comparer.cs                  | 2 +-
 .../src/System/Collections/Generic/EqualityComparer.cs          | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Comparer.cs b/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Comparer.cs
index 1e0ddf0b4b177..22cc2f3aac02c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Comparer.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Comparer.cs
@@ -86,7 +86,7 @@ public void GetObjectData(SerializationInfo info, StreamingContext context)
             if (!typeof(T).IsAssignableTo(typeof(IComparable<T>)))
             {
                 // We used to use NullableComparer only for types implementing IComparable<T>
-                info.SetType(typeof(ObjectComparer<T>));
+                info.SetType(typeof(ObjectComparer<T?>));
             }
         }
 
diff --git a/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/EqualityComparer.cs b/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/EqualityComparer.cs
index 127f35d150b9c..60a65072a41f9 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/EqualityComparer.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/EqualityComparer.cs
@@ -106,7 +106,7 @@ public void GetObjectData(SerializationInfo info, StreamingContext context)
             if (!typeof(T).IsAssignableTo(typeof(IEquatable<T>)))
             {
                 // We used to use NullableComparer only for types implementing IEquatable<T>
-                info.SetType(typeof(ObjectEqualityComparer<T>));
+                info.SetType(typeof(ObjectEqualityComparer<T?>));
             }
         }