diff --git a/llvm/include/llvm/ADT/BitVector.h b/llvm/include/llvm/ADT/BitVector.h
--- a/llvm/include/llvm/ADT/BitVector.h
+++ b/llvm/include/llvm/ADT/BitVector.h
@@ -29,7 +29,11 @@
 
 /// ForwardIterator for the bits that are set.
 /// Iterators get invalidated when resize / reserve is called.
-template <typename BitVectorT> class const_set_bits_iterator_impl {
+template <typename BitVectorT>
+class const_set_bits_iterator_impl
+    : public iterator_facade_base<
+          const_set_bits_iterator_impl<BitVectorT>, std::forward_iterator_tag,
+          unsigned, std::ptrdiff_t, const unsigned *, const unsigned &> {
   const BitVectorT &Parent;
   int Current = 0;