Index: clang/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- clang/lib/Sema/SemaDeclCXX.cpp
+++ clang/lib/Sema/SemaDeclCXX.cpp
@@ -14429,13 +14429,10 @@
   CXXRecordDecl *RD = CopyOp->getParent();
   CXXMethodDecl *UserDeclaredOperation = nullptr;
 
-  // In Microsoft mode, assignment operations don't affect constructors and
-  // vice versa.
   if (RD->hasUserDeclaredDestructor()) {
     UserDeclaredOperation = RD->getDestructor();
   } else if (!isa<CXXConstructorDecl>(CopyOp) &&
-             RD->hasUserDeclaredCopyConstructor() &&
-             !S.getLangOpts().MSVCCompat) {
+             RD->hasUserDeclaredCopyConstructor()) {
     // Find any user-declared copy constructor.
     for (auto *I : RD->ctors()) {
       if (I->isCopyConstructor()) {
@@ -14445,8 +14442,7 @@
     }
     assert(UserDeclaredOperation);
   } else if (isa<CXXConstructorDecl>(CopyOp) &&
-             RD->hasUserDeclaredCopyAssignment() &&
-             !S.getLangOpts().MSVCCompat) {
+             RD->hasUserDeclaredCopyAssignment()) {
     // Find any user-declared move assignment operator.
     for (auto *I : RD->methods()) {
       if (I->isCopyAssignmentOperator()) {
Index: clang/test/SemaCXX/deprecated-copy-msvc.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/deprecated-copy-msvc.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 %s -std=c++11 %s -Wdeprecated-copy -verify -fms-compatibility
+
+struct A {
+  A& operator=(const A&) = default; // expected-warning {{definition of implicit copy constructor for 'A' is deprecated because it has a user-declared copy assignment operator}}
+};
+
+struct B {
+  B& operator=(const B&) = delete; // expected-warning {{definition of implicit copy constructor for 'B' is deprecated because it has a user-declared copy assignment operator}}
+};
+
+void test() {
+  A a1;
+  A a2(a1); // expected-note {{implicit copy constructor for 'A' first required here}}
+
+  B b1;
+  B b2(b1); // expected-note {{implicit copy constructor for 'B' first required here}}
+}
+
+// PR45634
+struct S {
+  int i;
+  S& operator=(const S&) = delete; // expected-warning {{definition of implicit copy constructor for 'S' is deprecated because it has a user-declared copy assignment operator}}
+};
+
+S test(const S &s) { return S(s); } // expected-note {{implicit copy constructor for 'S' first required here}}