diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 3e1fb05ad537c..02a6fb5333538 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -3602,6 +3602,9 @@ class MemberPointerType : public Type, public llvm::FoldingSetNode {
   }
 
   NestedNameSpecifier *getQualifier() const { return Qualifier; }
+  /// Note: this can trigger extra deserialization when external AST sources are
+  /// used. Prefer `getCXXRecordDecl()` unless you really need the most recent
+  /// decl.
   CXXRecordDecl *getMostRecentCXXRecordDecl() const;
 
   bool isSugared() const;
@@ -3610,7 +3613,10 @@ class MemberPointerType : public Type, public llvm::FoldingSetNode {
   }
 
   void Profile(llvm::FoldingSetNodeID &ID) {
-    Profile(ID, getPointeeType(), getQualifier(), getMostRecentCXXRecordDecl());
+    // FIXME: `getMostRecentCXXRecordDecl()` should be possible to use here,
+    // however when external AST sources are used it causes nondeterminism
+    // issues (see https://github.com/llvm/llvm-project/pull/137910).
+    Profile(ID, getPointeeType(), getQualifier(), getCXXRecordDecl());
   }
 
   static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
@@ -3620,6 +3626,9 @@ class MemberPointerType : public Type, public llvm::FoldingSetNode {
   static bool classof(const Type *T) {
     return T->getTypeClass() == MemberPointer;
   }
+
+private:
+  CXXRecordDecl *getCXXRecordDecl() const;
 };
 
 /// Capture whether this is a normal array (e.g. int X[4])
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 111a642173418..a149eac7e4555 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5275,10 +5275,14 @@ void MemberPointerType::Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
     ID.AddPointer(Cls->getCanonicalDecl());
 }
 
+CXXRecordDecl *MemberPointerType::getCXXRecordDecl() const {
+  return dyn_cast<MemberPointerType>(getCanonicalTypeInternal())
+      ->getQualifier()
+      ->getAsRecordDecl();
+}
+
 CXXRecordDecl *MemberPointerType::getMostRecentCXXRecordDecl() const {
-  auto *RD = dyn_cast<MemberPointerType>(getCanonicalTypeInternal())
-                 ->getQualifier()
-                 ->getAsRecordDecl();
+  auto *RD = getCXXRecordDecl();
   if (!RD)
     return nullptr;
   return RD->getMostRecentNonInjectedDecl();