diff --git a/clang/include/clang/Basic/SourceManager.h b/clang/include/clang/Basic/SourceManager.h
index dfce3508e265..ae5f2bde37e6 100644
--- a/clang/include/clang/Basic/SourceManager.h
+++ b/clang/include/clang/Basic/SourceManager.h
@@ -39,6 +39,7 @@
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
@@ -620,7 +621,7 @@ class SourceManager : public RefCountedBase<SourceManager> {
   /// have already been loaded from the external source.
   ///
   /// Same indexing as LoadedSLocEntryTable.
-  std::vector<bool> SLocEntryLoaded;
+  llvm::BitVector SLocEntryLoaded;
 
   /// \brief An external source for source location entries.
   ExternalSLocEntrySource *ExternalSLocEntries;