diff --git a/clang-tools-extra/clangd/CMakeLists.txt b/clang-tools-extra/clangd/CMakeLists.txt
index d797ddce8c44d..6f10afe4a5625 100644
--- a/clang-tools-extra/clangd/CMakeLists.txt
+++ b/clang-tools-extra/clangd/CMakeLists.txt
@@ -91,7 +91,6 @@ add_clang_library(clangDaemon STATIC
   GlobalCompilationDatabase.cpp
   Headers.cpp
   HeaderSourceSwitch.cpp
-  HeuristicResolver.cpp
   Hover.cpp
   IncludeCleaner.cpp
   IncludeFixer.cpp
diff --git a/clang-tools-extra/clangd/FindTarget.cpp b/clang-tools-extra/clangd/FindTarget.cpp
index e702c6b3537a0..04fd6d437b7bd 100644
--- a/clang-tools-extra/clangd/FindTarget.cpp
+++ b/clang-tools-extra/clangd/FindTarget.cpp
@@ -8,7 +8,6 @@
 
 #include "FindTarget.h"
 #include "AST.h"
-#include "HeuristicResolver.h"
 #include "support/Logger.h"
 #include "clang/AST/ASTConcept.h"
 #include "clang/AST/ASTTypeTraits.h"
@@ -35,6 +34,7 @@
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Specifiers.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
diff --git a/clang-tools-extra/clangd/FindTarget.h b/clang-tools-extra/clangd/FindTarget.h
index b41c547095100..a7706804ce7ec 100644
--- a/clang-tools-extra/clangd/FindTarget.h
+++ b/clang-tools-extra/clangd/FindTarget.h
@@ -33,9 +33,11 @@
 #include <bitset>
 
 namespace clang {
-namespace clangd {
+
 class HeuristicResolver;
 
+namespace clangd {
+
 /// Describes the link between an AST node and a Decl it refers to.
 enum class DeclRelation : unsigned;
 /// A bitfield of DeclRelations.
diff --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
index fefffeb4efc1a..1b1bcf78c9855 100644
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -9,7 +9,6 @@
 #include "../clang-tidy/utils/DesignatedInitializers.h"
 #include "AST.h"
 #include "Config.h"
-#include "HeuristicResolver.h"
 #include "ParsedAST.h"
 #include "Protocol.h"
 #include "SourceCode.h"
@@ -27,6 +26,7 @@
 #include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
diff --git a/clang-tools-extra/clangd/ParsedAST.cpp b/clang-tools-extra/clangd/ParsedAST.cpp
index 725cbeb154cb8..89d6f26d0f150 100644
--- a/clang-tools-extra/clangd/ParsedAST.cpp
+++ b/clang-tools-extra/clangd/ParsedAST.cpp
@@ -20,7 +20,6 @@
 #include "Feature.h"
 #include "FeatureModule.h"
 #include "Headers.h"
-#include "HeuristicResolver.h"
 #include "IncludeCleaner.h"
 #include "IncludeFixer.h"
 #include "Preamble.h"
@@ -53,6 +52,7 @@
 #include "clang/Lex/Lexer.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/Serialization/ASTWriter.h"
 #include "clang/Tooling/CompilationDatabase.h"
 #include "clang/Tooling/Core/Diagnostic.h"
diff --git a/clang-tools-extra/clangd/ParsedAST.h b/clang-tools-extra/clangd/ParsedAST.h
index 8d9d1e6456926..82fac96360488 100644
--- a/clang-tools-extra/clangd/ParsedAST.h
+++ b/clang-tools-extra/clangd/ParsedAST.h
@@ -38,9 +38,9 @@
 #include <vector>
 
 namespace clang {
+class HeuristicResolver;
 class Sema;
 namespace clangd {
-class HeuristicResolver;
 
 /// Stores and provides access to parsed AST.
 class ParsedAST {
diff --git a/clang-tools-extra/clangd/SemanticHighlighting.cpp b/clang-tools-extra/clangd/SemanticHighlighting.cpp
index e6d16af2495fe..86ca05644c703 100644
--- a/clang-tools-extra/clangd/SemanticHighlighting.cpp
+++ b/clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -9,7 +9,6 @@
 #include "SemanticHighlighting.h"
 #include "Config.h"
 #include "FindTarget.h"
-#include "HeuristicResolver.h"
 #include "ParsedAST.h"
 #include "Protocol.h"
 #include "SourceCode.h"
@@ -27,6 +26,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/Tooling/Syntax/Tokens.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp
index 8d5ab2e491a40..0a093108b752c 100644
--- a/clang-tools-extra/clangd/XRefs.cpp
+++ b/clang-tools-extra/clangd/XRefs.cpp
@@ -10,7 +10,6 @@
 #include "FindSymbols.h"
 #include "FindTarget.h"
 #include "Headers.h"
-#include "HeuristicResolver.h"
 #include "IncludeCleaner.h"
 #include "ParsedAST.h"
 #include "Protocol.h"
@@ -53,6 +52,7 @@
 #include "clang/Index/IndexingOptions.h"
 #include "clang/Index/USRGeneration.h"
 #include "clang/Lex/Lexer.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/Tooling/Syntax/Tokens.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
diff --git a/clang-tools-extra/clangd/unittests/CMakeLists.txt b/clang-tools-extra/clangd/unittests/CMakeLists.txt
index 8dba8088908d5..dffdcd5d014ca 100644
--- a/clang-tools-extra/clangd/unittests/CMakeLists.txt
+++ b/clang-tools-extra/clangd/unittests/CMakeLists.txt
@@ -64,7 +64,6 @@ add_unittest(ClangdUnitTests ClangdTests
   GlobalCompilationDatabaseTests.cpp
   HeadersTests.cpp
   HeaderSourceSwitchTests.cpp
-  HeuristicResolverTests.cpp
   HoverTests.cpp
   IncludeCleanerTests.cpp
   IndexActionTests.cpp
diff --git a/clang-tools-extra/clangd/HeuristicResolver.h b/clang/include/clang/Sema/HeuristicResolver.h
similarity index 95%
rename from clang-tools-extra/clangd/HeuristicResolver.h
rename to clang/include/clang/Sema/HeuristicResolver.h
index c130e0677e86d..947de7a4e83ce 100644
--- a/clang-tools-extra/clangd/HeuristicResolver.h
+++ b/clang/include/clang/Sema/HeuristicResolver.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_HEURISTICRESOLVER_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_HEURISTICRESOLVER_H
+#ifndef LLVM_CLANG_SEMA_HEURISTICRESOLVER_H
+#define LLVM_CLANG_SEMA_HEURISTICRESOLVER_H
 
 #include "clang/AST/Decl.h"
 #include <vector>
@@ -24,8 +24,6 @@ class NamedDecl;
 class Type;
 class UnresolvedUsingValueDecl;
 
-namespace clangd {
-
 // This class handles heuristic resolution of declarations and types in template
 // code.
 //
@@ -80,7 +78,6 @@ class HeuristicResolver {
   ASTContext &Ctx;
 };
 
-} // namespace clangd
 } // namespace clang
 
 #endif
diff --git a/clang/lib/Sema/CMakeLists.txt b/clang/lib/Sema/CMakeLists.txt
index 3241cb53f004c..dbe4c1437897a 100644
--- a/clang/lib/Sema/CMakeLists.txt
+++ b/clang/lib/Sema/CMakeLists.txt
@@ -19,6 +19,7 @@ add_clang_library(clangSema
   CodeCompleteConsumer.cpp
   DeclSpec.cpp
   DelayedDiagnostic.cpp
+  HeuristicResolver.cpp
   HLSLExternalSemaSource.cpp
   IdentifierResolver.cpp
   JumpDiagnostics.cpp
diff --git a/clang-tools-extra/clangd/HeuristicResolver.cpp b/clang/lib/Sema/HeuristicResolver.cpp
similarity index 99%
rename from clang-tools-extra/clangd/HeuristicResolver.cpp
rename to clang/lib/Sema/HeuristicResolver.cpp
index 9eb892e8e4a8e..7c1b8450b9633 100644
--- a/clang-tools-extra/clangd/HeuristicResolver.cpp
+++ b/clang/lib/Sema/HeuristicResolver.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "HeuristicResolver.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/CXXInheritance.h"
 #include "clang/AST/DeclTemplate.h"
@@ -14,7 +14,6 @@
 #include "clang/AST/Type.h"
 
 namespace clang {
-namespace clangd {
 
 namespace {
 
@@ -466,5 +465,4 @@ const Type *HeuristicResolver::getPointeeType(const Type *T) const {
   return HeuristicResolverImpl(Ctx).getPointeeType(T);
 }
 
-} // namespace clangd
 } // namespace clang
diff --git a/clang/unittests/Sema/CMakeLists.txt b/clang/unittests/Sema/CMakeLists.txt
index 7ded562e8edfa..17d39408000a4 100644
--- a/clang/unittests/Sema/CMakeLists.txt
+++ b/clang/unittests/Sema/CMakeLists.txt
@@ -6,6 +6,7 @@ set(LLVM_LINK_COMPONENTS
 add_clang_unittest(SemaTests
   ExternalSemaSourceTest.cpp
   CodeCompleteTest.cpp
+  HeuristicResolverTest.cpp
   GslOwnerPointerInference.cpp
   SemaLookupTest.cpp
   SemaNoloadLookupTest.cpp
diff --git a/clang-tools-extra/clangd/unittests/HeuristicResolverTests.cpp b/clang/unittests/Sema/HeuristicResolverTest.cpp
similarity index 99%
rename from clang-tools-extra/clangd/unittests/HeuristicResolverTests.cpp
rename to clang/unittests/Sema/HeuristicResolverTest.cpp
index e4b3822fc7eb7..c4f054683ccdc 100644
--- a/clang-tools-extra/clangd/unittests/HeuristicResolverTests.cpp
+++ b/clang/unittests/Sema/HeuristicResolverTest.cpp
@@ -5,7 +5,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#include "HeuristicResolver.h"
+#include "clang/Sema/HeuristicResolver.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/Tooling/Tooling.h"
@@ -13,7 +13,6 @@
 #include "gtest/gtest.h"
 
 using namespace clang::ast_matchers;
-using clang::clangd::HeuristicResolver;
 using testing::ElementsAre;
 
 namespace clang {