Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -9632,15 +9632,11 @@
     }
 
     if (isFriend) {
-      // In MSVC mode for older versions of the standard, friend function
-      // declarations behave as declarations
-      bool PerformFriendInjection =
-          getLangOpts().MSVCCompat && !getLangOpts().CPlusPlus20;
       if (FunctionTemplate) {
-        FunctionTemplate->setObjectOfFriendDecl(PerformFriendInjection);
+        FunctionTemplate->setObjectOfFriendDecl();
         FunctionTemplate->setAccess(AS_public);
       }
-      NewFD->setObjectOfFriendDecl(PerformFriendInjection);
+      NewFD->setObjectOfFriendDecl();
       NewFD->setAccess(AS_public);
     }
 
Index: clang/test/SemaCXX/ms-friend-function-decl.cpp
===================================================================
--- clang/test/SemaCXX/ms-friend-function-decl.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-// RUN: %clang_cc1 -std=c++03 -fms-compatibility -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++17 -fms-compatibility -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++20 -fms-compatibility -fsyntax-only -verify=modern %s
-#if __cplusplus < 202002L
-// expected-no-diagnostics
-#endif
-
-namespace ns {
-
-class C {
-public:
-  template <typename T>
-  friend void funtemp();
-
-  friend void fun();
-
-  void test() {
-    ::ns::fun(); // modern-error {{no member named 'fun' in namespace 'ns'}}
-
-    // modern-error@+3 {{no member named 'funtemp' in namespace 'ns'}}
-    // modern-error@+2 {{expected '(' for function-style cast or type construction}}
-    // modern-error@+1 {{expected expression}}
-    ::ns::funtemp<int>();
-  }
-};
-
-void fun() {
-}
-
-template <typename T>
-void funtemp() {}
-
-} // namespace ns
-
-class Glob {
-public:
-  friend void funGlob();
-
-  void test() {
-    funGlob(); // modern-error {{use of undeclared identifier 'funGlob'}}
-  }
-};
-
-void funGlob() {
-}
Index: clang/unittests/AST/ASTImporterTest.cpp
===================================================================
--- clang/unittests/AST/ASTImporterTest.cpp
+++ clang/unittests/AST/ASTImporterTest.cpp
@@ -2658,10 +2658,7 @@
       getTuDecl("struct X { friend void f(); };", Lang_CXX03, "input0.cc");
   auto *FromD = FirstDeclMatcher<FunctionDecl>().match(FromTU, FunctionPattern);
   ASSERT_TRUE(FromD->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
-  // Before CXX20, MSVC treats friend function declarations as function
-  // declarations
-  ASSERT_EQ(FromTU->getLangOpts().MSVCCompat,
-            FromD->isInIdentifierNamespace(Decl::IDNS_Ordinary));
+  ASSERT_FALSE(FromD->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   {
     auto FromName = FromD->getDeclName();
     auto *Class = FirstDeclMatcher<CXXRecordDecl>().match(FromTU, ClassPattern);
@@ -2705,10 +2702,7 @@
   auto *FromNormal =
       LastDeclMatcher<FunctionDecl>().match(FromTU, FunctionPattern);
   ASSERT_TRUE(FromFriend->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
-  // Before CXX20, MSVC treats friend function declarations as function
-  // declarations
-  ASSERT_EQ(FromTU->getLangOpts().MSVCCompat,
-            FromFriend->isInIdentifierNamespace(Decl::IDNS_Ordinary));
+  ASSERT_FALSE(FromFriend->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   ASSERT_FALSE(FromNormal->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
   ASSERT_TRUE(FromNormal->isInIdentifierNamespace(Decl::IDNS_Ordinary));
 
@@ -2799,10 +2793,7 @@
 
   ASSERT_TRUE(FromNormalF->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   ASSERT_FALSE(FromNormalF->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
-  // Before CXX20, MSVC treats friend function declarations as function
-  // declarations
-  ASSERT_EQ(FromFriendTU->getLangOpts().MSVCCompat,
-            FromFriendF->isInIdentifierNamespace(Decl::IDNS_Ordinary));
+  ASSERT_FALSE(FromFriendF->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   ASSERT_TRUE(FromFriendF->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
   auto LookupRes = FromNormalTU->noload_lookup(FromNormalName);
   ASSERT_TRUE(LookupRes.isSingleResult());