diff --git a/clang/include/clang/Sema/SemaObjC.h b/clang/include/clang/Sema/SemaObjC.h
index b868e9e7cd0aa9..9367c680953f71 100644
--- a/clang/include/clang/Sema/SemaObjC.h
+++ b/clang/include/clang/Sema/SemaObjC.h
@@ -208,23 +208,8 @@ class SemaObjC : public SemaBase {
   /// of -Wselector.
   llvm::MapVector<Selector, SourceLocation> ReferencedSelectors;
 
-  class GlobalMethodPool {
-  public:
-    using Lists = std::pair<ObjCMethodList, ObjCMethodList>;
-    using iterator = llvm::DenseMap<Selector, Lists>::iterator;
-    iterator begin() { return Methods.begin(); }
-    iterator end() { return Methods.end(); }
-    iterator find(Selector Sel) { return Methods.find(Sel); }
-    std::pair<iterator, bool> insert(std::pair<Selector, Lists> &&Val) {
-      return Methods.insert(Val);
-    }
-    Lists &operator[](Selector Key) { return Methods[Key]; }
-    int count(Selector Sel) const { return Methods.count(Sel); }
-    bool empty() const { return Methods.empty(); }
-
-  private:
-    llvm::DenseMap<Selector, Lists> Methods;
-  };
+  using GlobalMethodPool =
+      llvm::DenseMap<Selector, std::pair<ObjCMethodList, ObjCMethodList>>;
 
   /// Method Pool - allows efficient lookup when typechecking messages to "id".
   /// We need to maintain a list, since selectors can have differing signatures
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 87be43b13813d3..d8cd09b8272930 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -3649,7 +3649,7 @@ ObjCMethodDecl *SemaObjC::LookupImplementedMethodInGlobalPool(Selector Sel) {
   if (Pos == MethodPool.end())
     return nullptr;
 
-  GlobalMethodPool::Lists &Methods = Pos->second;
+  auto &Methods = Pos->second;
   for (const ObjCMethodList *Method = &Methods.first; Method;
        Method = Method->getNext())
     if (Method->getMethod() &&
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 7efcc81e194d95..47a286be2303fd 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8751,22 +8751,18 @@ void ASTReader::ReadMethodPool(Selector Sel) {
     return;
 
   Sema &S = *getSema();
-  SemaObjC::GlobalMethodPool::iterator Pos =
-      S.ObjC()
-          .MethodPool
-          .insert(std::make_pair(Sel, SemaObjC::GlobalMethodPool::Lists()))
-          .first;
+  auto &Methods = S.ObjC().MethodPool[Sel];
 
-  Pos->second.first.setBits(Visitor.getInstanceBits());
-  Pos->second.first.setHasMoreThanOneDecl(Visitor.instanceHasMoreThanOneDecl());
-  Pos->second.second.setBits(Visitor.getFactoryBits());
-  Pos->second.second.setHasMoreThanOneDecl(Visitor.factoryHasMoreThanOneDecl());
+  Methods.first.setBits(Visitor.getInstanceBits());
+  Methods.first.setHasMoreThanOneDecl(Visitor.instanceHasMoreThanOneDecl());
+  Methods.second.setBits(Visitor.getFactoryBits());
+  Methods.second.setHasMoreThanOneDecl(Visitor.factoryHasMoreThanOneDecl());
 
   // Add methods to the global pool *after* setting hasMoreThanOneDecl, since
   // when building a module we keep every method individually and may need to
   // update hasMoreThanOneDecl as we add the methods.
-  addMethodsToPool(S, Visitor.getInstanceMethods(), Pos->second.first);
-  addMethodsToPool(S, Visitor.getFactoryMethods(), Pos->second.second);
+  addMethodsToPool(S, Visitor.getInstanceMethods(), Methods.first);
+  addMethodsToPool(S, Visitor.getFactoryMethods(), Methods.second);
 }
 
 void ASTReader::updateOutOfDateSelector(Selector Sel) {