diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index 58e01bf0f051..84528067012b 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -3918,6 +3918,7 @@ class MSPropertyDecl : public DeclaratorDecl {
       : DeclaratorDecl(MSProperty, DC, L, N, T, TInfo, StartL),
         GetterId(Getter), SetterId(Setter) {}
 
+  void anchor() override;
 public:
   friend class ASTDeclReader;
 
diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
index 9e01c4950d75..f6e3d8f300ba 100644
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -751,6 +751,7 @@ class RedeclarableTemplateDecl : public TemplateDecl,
     return getMostRecentDecl();
   }
 
+  void anchor() override;
 protected:
   template <typename EntryType> struct SpecEntryTraits {
     using DeclType = EntryType;
diff --git a/clang/include/clang/Lex/ModuleMap.h b/clang/include/clang/Lex/ModuleMap.h
index 4daa1dd817b6..a38c8d7819db 100644
--- a/clang/include/clang/Lex/ModuleMap.h
+++ b/clang/include/clang/Lex/ModuleMap.h
@@ -45,6 +45,8 @@ class SourceManager;
 /// A mechanism to observe the actions of the module map parser as it
 /// reads module map files.
 class ModuleMapCallbacks {
+  virtual void anchor();
+
 public:
   virtual ~ModuleMapCallbacks() = default;
 
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 33f159417b71..2893fca859ed 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -2910,6 +2910,8 @@ void DecompositionDecl::printName(llvm::raw_ostream &os) const {
   os << ']';
 }
 
+void MSPropertyDecl::anchor() {}
+
 MSPropertyDecl *MSPropertyDecl::Create(ASTContext &C, DeclContext *DC,
                                        SourceLocation L, DeclarationName N,
                                        QualType T, TypeSourceInfo *TInfo,
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index 04e1803281be..76f29dac1647 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -149,6 +149,8 @@ void *allocateDefaultArgStorageChain(const ASTContext &C) {
 // RedeclarableTemplateDecl Implementation
 //===----------------------------------------------------------------------===//
 
+void RedeclarableTemplateDecl::anchor() {}
+
 RedeclarableTemplateDecl::CommonBase *RedeclarableTemplateDecl::getCommonPtr() const {
   if (Common)
     return Common;
diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 13d2b728f58c..cff950b703a6 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -54,6 +54,8 @@
 
 using namespace clang;
 
+void ModuleMapCallbacks::anchor() {}
+
 void ModuleMap::resolveLinkAsDependencies(Module *Mod) {
   auto PendingLinkAs = PendingLinkAsModule.find(Mod->Name);
   if (PendingLinkAs != PendingLinkAsModule.end()) {