diff --git a/include/algorithm b/include/algorithm
index 3d8bf7a..f357177 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -321,7 +321,7 @@
     stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
 
 template<class ForwardIterator, class Predicate>
-    ForwardIterator
+    ForwardIterator  // constexpr in C++20
     partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
 
 template <class ForwardIterator>
@@ -3328,7 +3328,7 @@
 // partition_point
 
 template<class _ForwardIterator, class _Predicate>
-_ForwardIterator
+_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
 {
     typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;