diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 623a4b3c18bb1..1ae35e6881d2f 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -47,6 +47,12 @@ C++ Specific Potentially Breaking Changes
 
 ABI Changes in This Version
 ---------------------------
+- Fixed Microsoft name mangling of implicitly defined variables used for thread
+  safe static initialization of static local variables. This change resolves
+  incompatibilities with code compiled by MSVC but might introduce
+  incompatibilities with code compiled by earlier versions of Clang when an
+  inline member function that contains a static local variable with a dynamic
+  initializer is declared with ``__declspec(dllimport)``. (#GH83616).
 
 AST Dumping Potentially Breaking Changes
 ----------------------------------------
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index b272a546573a3..aa26bb7ed46f4 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -390,6 +390,7 @@ class MicrosoftCXXNameMangler {
                           const FunctionDecl *D = nullptr,
                           bool ForceThisQuals = false,
                           bool MangleExceptionSpec = true);
+  void mangleSourceName(StringRef Name);
   void mangleNestedName(GlobalDecl GD);
 
 private:
@@ -408,7 +409,6 @@ class MicrosoftCXXNameMangler {
     mangleUnqualifiedName(GD, cast<NamedDecl>(GD.getDecl())->getDeclName());
   }
   void mangleUnqualifiedName(GlobalDecl GD, DeclarationName Name);
-  void mangleSourceName(StringRef Name);
   void mangleOperatorName(OverloadedOperatorKind OO, SourceLocation Loc);
   void mangleCXXDtorType(CXXDtorType T);
   void mangleQualifiers(Qualifiers Quals, bool IsMember);
@@ -3920,7 +3920,8 @@ void MicrosoftMangleContextImpl::mangleThreadSafeStaticGuardVariable(
   msvc_hashing_ostream MHO(Out);
   MicrosoftCXXNameMangler Mangler(*this, MHO);
 
-  Mangler.getStream() << "?$TSS" << GuardNum << '@';
+  Mangler.getStream() << "?";
+  Mangler.mangleSourceName("$TSS" + llvm::utostr(GuardNum));
   Mangler.mangleNestedName(VD);
   Mangler.getStream() << "@4HA";
 }
diff --git a/clang/test/CodeGenCXX/mangle-ms-back-references.cpp b/clang/test/CodeGenCXX/mangle-ms-back-references.cpp
index cb95c100b3d22..b27a9c5acacb7 100644
--- a/clang/test/CodeGenCXX/mangle-ms-back-references.cpp
+++ b/clang/test/CodeGenCXX/mangle-ms-back-references.cpp
@@ -83,3 +83,20 @@ class H;
 
 void ManyParams(T01 &, T02 &, T03 &, T04 &, T05 &, T06 &, T07 &, T08 &, T09 &, T10 &, H<T11> &, H<T11> &) {}
 // CHECK: "?ManyParams@@YAXAAVT01@@AAVT02@@AAVT03@@AAVT04@@AAVT05@@AAVT06@@AAVT07@@AAVT08@@AAVT09@@AAVT10@@AAV?$H@VT11@@@@AAV?$H@VT11@@@@@Z"
+
+namespace NS {
+// The name "TSS0" for the name of the class below has been specifically
+// chosen to ensure that back reference lookup does not match against the
+// implicitly generated "$TSS0" name of the thread safe static initialization
+// variable.
+struct __declspec(dllexport) TSS0 {
+  static TSS0& get();
+  __forceinline static TSS0& singleton() {
+    static TSS0& lsv = get();
+    return lsv;
+  }
+};
+}
+// CHECK: "?singleton@TSS0@NS@@SAAAU12@XZ"
+// CHECK: "?lsv@?1??singleton@TSS0@NS@@SAAAU23@XZ@4AAU23@A"
+// CHECK: "?$TSS0@?1??singleton@TSS0@NS@@SAAAU23@XZ@4HA"