diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 2fd231b..1234afb 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3416,6 +3416,17 @@
   return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg());
 }
 
+// The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
+// disambiguate entities defined in different scopes.
+// While the VS2015 ABI fixes potential miscompiles, it is also breaks
+// compatibility.
+// We will pick our mangling number depending on which version of MSVC is being
+// targeted.
+static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
+  return LO.isCompatibleWithMSVC(19) ? S->getMSCurManglingNumber()
+                                     : S->getMSLastManglingNumber();
+}
+
 void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
   if (!Context.getLangOpts().CPlusPlus)
     return;
@@ -3428,7 +3439,8 @@
     MangleNumberingContext &MCtx =
         Context.getManglingNumberContext(Tag->getParent());
     Context.setManglingNumber(
-        Tag, MCtx.getManglingNumber(Tag, TagScope->getMSLocalManglingNumber()));
+        Tag, MCtx.getManglingNumber(
+                 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
     return;
   }
 
@@ -3437,8 +3449,8 @@
   if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
           Tag->getDeclContext(), ManglingContextDecl)) {
     Context.setManglingNumber(
-        Tag,
-        MCtx->getManglingNumber(Tag, TagScope->getMSLocalManglingNumber()));
+        Tag, MCtx->getManglingNumber(
+                 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
   }
 }
 
@@ -4135,10 +4147,11 @@
   if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
     if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
       Decl *ManglingContextDecl;
-      if (MangleNumberingContext *MCtx =
-              getCurrentMangleNumberContext(NewVD->getDeclContext(),
-                                            ManglingContextDecl)) {
-        Context.setManglingNumber(NewVD, MCtx->getManglingNumber(NewVD, S->getMSLocalManglingNumber()));
+      if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
+              NewVD->getDeclContext(), ManglingContextDecl)) {
+        Context.setManglingNumber(
+            NewVD, MCtx->getManglingNumber(
+                       NewVD, getMSManglingNumber(getLangOpts(), S)));
         Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
       }
     }
@@ -5925,11 +5938,11 @@
 
   if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
     Decl *ManglingContextDecl;
-    if (MangleNumberingContext *MCtx =
-            getCurrentMangleNumberContext(NewVD->getDeclContext(),
-                                          ManglingContextDecl)) {
+    if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
+            NewVD->getDeclContext(), ManglingContextDecl)) {
       Context.setManglingNumber(
-          NewVD, MCtx->getManglingNumber(NewVD, S->getMSLocalManglingNumber()));
+          NewVD, MCtx->getManglingNumber(
+                     NewVD, getMSManglingNumber(getLangOpts(), S)));
       Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
     }
   }