Index: lib/Sema/SemaDeclCXX.cpp
===================================================================
--- lib/Sema/SemaDeclCXX.cpp
+++ lib/Sema/SemaDeclCXX.cpp
@@ -4377,11 +4377,24 @@
   // specialization bases.
 
   for (Decl *Member : Class->decls()) {
-    if (!isa<CXXMethodDecl>(Member) && !isa<VarDecl>(Member))
+    VarDecl *VD = dyn_cast<VarDecl>(Member);
+    CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
+
+    // Only methods and static fields inherit the attributes.
+    if (!VD && !MD)
       continue;
-    if (isa<CXXMethodDecl>(Member) && cast<CXXMethodDecl>(Member)->isDeleted())
+
+    // Don't process deleted methods.
+    if (MD && MD->isDeleted())
       continue;
 
+    if (MD && MD->isMoveAssignmentOperator() && !ClassExported &&
+        MD->isInlined()) {
+      // Current MSVC versions don't export the move assignment operators, so
+      // don't attempt to import them if we have a definition.
+      continue;
+    }
+
     if (InheritableAttr *MemberAttr = getDLLAttr(Member)) {
       if (S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
           !MemberAttr->isInherited()) {
Index: test/CodeGenCXX/dllimport.cpp
===================================================================
--- test/CodeGenCXX/dllimport.cpp
+++ test/CodeGenCXX/dllimport.cpp
@@ -27,6 +27,8 @@
 #define USE(func) void UNIQ(use)() { func(); }
 #define USEMEMFUNC(class, func) void (class::*UNIQ(use)())() { return &class::func; }
 #define USECLASS(class) void UNIQ(USE)() { class x; }
+#define USECOPYASSIGN(class) class& (class::*UNIQ(use)())(class&) { return &class::operator=; }
+#define USEMOVEASSIGN(class) class& (class::*UNIQ(use)())(class&&) { return &class::operator=; }
 
 //===----------------------------------------------------------------------===//
 // Globals
@@ -518,9 +520,18 @@
 
   static int b;
   // MO1-DAG: @"\01?b@T@@2HA" = external dllimport global i32
+
+  T& operator=(T&) = default;
+  // MO1-DAG: define available_externally dllimport x86_thiscallcc nonnull %struct.T* @"\01??4T@@QAEAAU0@AAU0@@Z"
+
+  T& operator=(T&&) = default;
+  // Note: Don't mark inline move operators dllimport because current MSVC versions don't export them.
+  // MO1-DAG: define linkonce_odr x86_thiscallcc nonnull %struct.T* @"\01??4T@@QAEAAU0@$$QAU0@@Z"
 };
 USEMEMFUNC(T, a)
 USEVAR(T::b)
+USECOPYASSIGN(T)
+USEMOVEASSIGN(T)
 
 template <typename T> struct __declspec(dllimport) U { void foo() {} };
 // MO1-DAG: define available_externally dllimport x86_thiscallcc void @"\01?foo@?$U@H@@QAEXXZ"