diff --git a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
--- a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -29,6 +29,7 @@
 #include "clang/Lex/Lexer.h"
 #include "clang/Tooling/Core/Diagnostic.h"
 #include "clang/Tooling/Core/Replacement.h"
+#include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
@@ -863,7 +864,7 @@
     }
   }
 
-  std::vector<bool> Apply(ErrorFixes.size(), true);
+  llvm::BitVector Apply(ErrorFixes.size(), true);
   for (auto &FileAndEvents : FileEvents) {
     std::vector<Event> &Events = FileAndEvents.second;
     // Sweep.
diff --git a/clang-tools-extra/clangd/Selection.cpp b/clang-tools-extra/clangd/Selection.cpp
--- a/clang-tools-extra/clangd/Selection.cpp
+++ b/clang-tools-extra/clangd/Selection.cpp
@@ -24,6 +24,7 @@
 #include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/Lexer.h"
 #include "clang/Tooling/Syntax/Tokens.h"
+#include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Casting.h"
@@ -260,7 +261,7 @@
         });
     auto Sel = llvm::makeArrayRef(SelFirst, SelLimit);
     // Find which of these are preprocessed to nothing and should be ignored.
-    std::vector<bool> PPIgnored(Sel.size(), false);
+    llvm::BitVector PPIgnored(Sel.size(), false);
     for (const syntax::TokenBuffer::Expansion &X :
          Buf.expansionsOverlapping(Sel)) {
       if (X.Expanded.empty()) {