diff --git a/clang/include/clang/Frontend/ASTUnit.h b/clang/include/clang/Frontend/ASTUnit.h
--- a/clang/include/clang/Frontend/ASTUnit.h
+++ b/clang/include/clang/Frontend/ASTUnit.h
@@ -756,7 +756,6 @@
       CaptureDiagsKind CaptureDiagnostics = CaptureDiagsKind::None,
       unsigned PrecompilePreambleAfterNParses = 0,
       bool CacheCodeCompletionResults = false,
-      bool IncludeBriefCommentsInCodeCompletion = false,
       bool UserFilesAreVolatile = false,
       std::unique_ptr<ASTUnit> *ErrAST = nullptr);
 
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1520,8 +1520,7 @@
     ASTUnit *Unit, bool Persistent, StringRef ResourceFilesPath,
     bool OnlyLocalDecls, CaptureDiagsKind CaptureDiagnostics,
     unsigned PrecompilePreambleAfterNParses, bool CacheCodeCompletionResults,
-    bool IncludeBriefCommentsInCodeCompletion, bool UserFilesAreVolatile,
-    std::unique_ptr<ASTUnit> *ErrAST) {
+    bool UserFilesAreVolatile, std::unique_ptr<ASTUnit> *ErrAST) {
   assert(CI && "A CompilerInvocation is required");
 
   std::unique_ptr<ASTUnit> OwnAST;
@@ -1544,8 +1543,7 @@
     AST->PreambleRebuildCountdown = PrecompilePreambleAfterNParses;
   AST->TUKind = Action ? Action->getTranslationUnitKind() : TU_Complete;
   AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
-  AST->IncludeBriefCommentsInCodeCompletion
-    = IncludeBriefCommentsInCodeCompletion;
+  AST->IncludeBriefCommentsInCodeCompletion = false;
 
   // Recover resources if we crash before exiting this method.
   llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
diff --git a/clang/tools/libclang/Indexing.cpp b/clang/tools/libclang/Indexing.cpp
--- a/clang/tools/libclang/Indexing.cpp
+++ b/clang/tools/libclang/Indexing.cpp
@@ -617,9 +617,7 @@
       std::move(CInvok), CXXIdx->getPCHContainerOperations(), Diags,
       IndexAction.get(), UPtr, Persistent, CXXIdx->getClangResourcesPath(),
       OnlyLocalDecls, CaptureDiagnostics, PrecompilePreambleAfterNParses,
-      CacheCodeCompletionResults,
-      /*IncludeBriefCommentsInCodeCompletion=*/false,
-      /*UserFilesAreVolatile=*/true);
+      CacheCodeCompletionResults, /*UserFilesAreVolatile=*/true);
   if (DiagTrap.hasErrorOccurred() && CXXIdx->getDisplayDiagnostics())
     printDiagsToStderr(UPtr);